Many iguana owners like to allow their lizards to roam free throughout the entire house or apartment, or at least one or two rooms. These are viable situations, but many important precautions must first be taken into consideration. As I will discuss shortly, iguanas need to live in very high temperatures if effective digestion is to take place. You will need to heat the areas that the iguana will occupy. In addition, it is not always particularly easy to potty-train iguanas, who generally defecate daily. Some iguanas will choose a particular spot (or maybe two or three particular spots) and use it faithfully. In that case, you can place a litter box or newspaper in that spot for easy cleaning. Other iguanas may use a certain area sometimes, but frequently stray from it. Still others will return to a particular spot thanks only to sheer coincidence. You must be prepared to deal with these daily clean-ups. Iguanas' stools can stain and many iguana owners already know that some of their lizards' favorite spots to relieve themselves are on beds and stacks of clean clothes. In addition to the problem of staining, general hygeine is extremely important. It is easy to put off cleaning an iguana mess if it's in the corner of a room, but that corner will soon become a breeding ground for harmful bacteria.
Another important consideration is iguana-proofing the rooms. Iguanas can be even more curious than cats, but unfortunately, tend to be much less graceful. If you have fragile objects on shelves, they are likely to be knocked over and possibly damaged by your iguana. Climbing is facilitated by your iguana's use of its claws. If much of your furniture is slippery (wood, as opposed to upholstery) your iguana will likely slip off and possibly injure itself. Electrical outlets can also be hazardous. Iguanas can get caught in between radiators and walls, get tangled in stereo wires, burn themselves on lightbulbs, or even decide to hang out underneath heavy furniture for several days at a time, thus missing meals and cooling down. You must also consider the iguana's general happiness: iguanas are arboreal, which means that they are tree-dwelling in the wild. They will want to climb the furniture, which may be impossible for them if their claws don't have anything to grab onto. Alternately, their claws might tear holes in your upholstery if too much wanton climbing takes place.
Despite all of the above warnings, there are indeed many iguanas that do share their living space with their owners. A suitable environment can be created if you carefully consider the above precautions. You might even consider adding some large branches to your decor for your iguanas to climb. You might also section off one corner of the room for use as an open cage. If you heat that area, supply branches and feed them there, they may spend much of their time in that area, only leaving for temporary changes of scenery and for exercise. One option is to hang a heat lamp from the ceiling, above your iguana's basking area. Iguanas like to bask in hot light (like the sun) and generally prefer to do that over merely sitting in a heated room. Some iguana owners are able to devote an entire room to their free-roaming lizards which can be completely iguana-proofed and decorated iguana-style. The air temperature in that room may be raised using a heater, but you should still provide basking sites. If you do choose to let your iguana free-roam, please read the rest of this section so you can learn about their light and temperature requirements.
Generally, owners of juvenile iguanas choose to house their lizards in aquariums or other types of cages. Small lizards are likely to get lost when released into large areas, so an enclosure of some kind is recommended. Aquariums tend to be the most popular choice, probably due to their availability. Glass surfaces are also easy to clean, and allow for high visibility. Some iguana owners opt to build cages for their lizards. A common type of custom cage is one with a wooden frame, with the sides made of cage wire or plexiglass. Glass can also be used, as it won't scratch or bend, but it is much heavier when coupled with the wooden frame and is more fragile during construction and when moving. Glass and plexiglass are popular because they tend to look nicer than cage wire, allow for optimum visibility of the lizard inside, and they also keep the heat in the cage. Cage wire, however, may be favored by the iguana because it will provide a climbing material, and also because it allows for ventilation. (It is also much less expensive.) It is crucial to keep the cage warm, but it is also important to allow the animal inside to breathe. In general, when constructing your iguana's cage, you must take many factors into consideration, which are discussed below. If you find that you cannot meet the requirements that are given, it would be a good idea to try to find your iguana a different home. Many people buy iguanas not realizing how much time and money they will need to invest in their new pets, and it is always best to find a better home for the iguana than put a half-hearted effort into caring for it.
As a general rule, you should offer your iguana the largest enclosure that you can possibly afford and have room for. Adult iguanas are arboreal, which means that they spend most of their time in trees in the wild. As juveniles, iguanas spend much more time on the ground, so smaller, shorter cages are acceptable for a while. But as iguanas grow, they want to climb. This means that you must provide an enclosure that has very much vertical space. If faced with the choice of one or the other, it would be better for you to provide a cage that is 7 feet tall than 7 feet wide or long. You may find that this sort of cage structure is advantageous to you as well, as you can then devote less floor space to your iguana's enclosure. If you are not sure if the cage you have in mind is large enough for an iguana, there are some general guidelines that can be followed: the cage should be at least as tall as the iguana is long. (Including tail.) Preferably taller. It should be about 1 1/2 times the total length of the animal in length, and 2/3 the total length of the animal in width. The iguana should have ample room to walk, turn around, and climb. These guidelines should be considered minimum standards. Your iguana will probably become quite depressed if it has less room than this in an enclosure that it will be spending much of its time in. (As a side note: I house my four iguanas in a cage that is six feet tall, eight feet long, and three feet wide, and I let them out frequently for exercise.)
Your iguana will not be happy if it doesn't have anything to do besides sitting on the floor of its cage. You must provide branches for climbing in the cage. The branches should be a little larger in diameter than your iguana at its largest point. Alternately, you could provide a different kind of climbing material such as a 2"x4" covered with carpet or with grooves cut into it. Climbing is a favorite pastime of green iguanas, and you must not deny them this option. The branches should sit diagonally within the cage. Most iguanas seem to like to sit atop high horizontal surfaces such as shelves, so you may wish to install a shelf near the high end of the branch. You may wish to make a place like this into your iguana's "basking spot", which will be discussed next. In addition to branches and shelves, some choose to add ropes or rope ladders. These are usually used for juvenile iguanas only. You must be careful with large iguanas because due to their weight, if they get tangled in a rope they can injure themselves. Make sure all the items in the cage are safe and secure to avoid any accidents!
Heating and Lighting
Heating and lighting the iguanaís enclosure are two problems that many people choose to solve at the same time. Incandescent (regular bulbs that screw into regular light sockets) spotlights, available from your hardware or lighting store in a wide variety of wattages, can keep your iguana's cage both warm and bright. This is my heating method of choice. By placing a spot light at one end of the cage, you can create a nice temperature gradient for your iguana, which is essential to its well being. The area directly under the light would be the basking spot, where your iguana will go to warm up early in the day. The basking spot should be in the mid-nineties. (Degrees Fahrenheit.) You might want to invest in an aquarium thermometer so that you may test the temperature at all parts of the cage. As the iguana gets farther away from the basking spot, the ambient temperature decreases. The coolest part of the cage should be around 80 degrees. As a general rule, iguanas need to maintain an internal temperature of 88 degrees for about 10 hours a day if effective digestion is to take place. My favorite way to mount the spot light is to screw it into a shop-light fixture, and set it right on the screen or wire top of the cage. Lights should never be placed inside the cage because iguanas will climb on them and burn themselves. If you do not have a screen or wire top to your cage, you could shine the light through a screen or wire side. (Some part of the cage must usually be screen or wire, or else there will not be enough ventilation! See Ventilation section.) If your cage has no screen or wire sides but still has effective ventilation, you could place a light bulb or ceramic heat emitter (which screws into a regular light bulb socket but emits no light) in the cage, but make sure to put wire or screen around it. You must use a thermometer, however, to make sure the inside of the cage is at the correct temperature.
There are also under tank heaters made to be placed under aquariums to warm the floor, which is suitable for young specimens that spend much of their time sitting on the floor of their cages. They are not very effective at warming up the air temperature inside aquariums so if you have an iguana that spends its time on branches or rocks that do not come into contact with the floor of the aquarium, an under tank heater will not do you much good. If you do invest in a floor heater, human heating pads are much less expensive and easier to control than the ones marketed for reptiles in pet stores. In addition, I recommend against using "hot rocks", as they are notorious for over-heating and burning reptiles on their ventral sides. Also, wild iguanas obtain their heat from the sun above, not rocks below. Hot rocks are kind of neat ideas in themselves in that the manufacturers have given you a mini heater in the shape of a rock, which might seem perfect for a reptile cage. But remember - the rock is just a heater, and in the author's experience, an unstable one at that. All of my hot rocks have "burned out" and are now useless except for decoration - probably because it is impossible to keep them from getting wet. I know several other people whose hot rocks have overheated, thus resulting in burns on their iguanas. In conclusion, the only really suitable methods I have found for heating iguana enclosures has been incandescent spot lights and regular space or room heaters. If you use a heater, make sure that the iguana cannot come into contact with it and knock it over or burn itself. Iguanas seem to be the happiest when they have a basking spot, so you may use a space heater to help heat the iguanaís area, but the iguana should really have a basking spot as well.
Vegetable matter contains a large amount of cellulose (which is the main component of plant cell walls) which most animals cannot digest on their own. Iguanas have microorganisms living in their hindgut which break down the cellulose for them. These microorganisms need hot temperatures in order to do their work, so if you keep your iguana too cool, one of the effects will be poor digestion, which will lead to problems stemming from malnutrition.
It is absolutely essential that your iguana be provided exposure to wide ranges of ultraviolet light. Natural sunlight is best. Iguanas' bodies synthesize vitamin D3 with exposure to UV-B light, and vitamin D3 is essential for calcium absorption. It is also speculated that there are many other physical and psychological benefits of UV light. If you can, you should take your iguana outside on sunny days, even if it not particularly hot. If your iguana does not usually live outside, you must purchase "full spectrum" fluorescent bulbs. There are many different brands on the market, and your local pet store can probably order whatever brand you want. (Lighting stores are generally useless for full spectrum bulbs.) You need a full spectrum, not broad spectrum, light, and if possible, you should buy a few bulbs, all different brands. None of the bulbs radiate exactly the same wavelengths, and like with diet, the widest range you can offer is the best thing you can do for your iguana.
These full spectrum bulbs can be inserted into any fluorescent "tube" light fixture. You can leave these bulbs on all day, for the same amount of time that you offer light. You must, however, offer UV light unfiltered through glass or plastic. If the light fixture you have has a plastic "shield", it must be removed. In addition, if your cage has a glass or plastic top, adjustments must be made so that your iguana can be exposed to unfiltered UV light.
It has been shown that incandescent "full spectrum" lights are nothing of the sort, and you should stick to the fluorescent (tube) variety.
The photoperiod is simply the length of time your iguana is exposed to light each day. The recommended photoperiod for iguanas is pretty simple: plug your heating lights and ultraviolet lights into a timer so that they turn on for about fourteen hours each day. As the seasons change, I alter my timer so that their lights turn on when the sun comes up, and turn off fourteen hours later. In addition to providing your iguana with its own lights for fourteen hours a day, it is essential that you do not keep lights near your iguana's enclosure on all night. The photoperiod is an important part of your iguana's life. It can become stressed if it never has periods of darkness. So if you are a nightowl and tend to stay up all night with lights and televisions on, please place your iguana's cage in a room that you would not spend time in.
For use as a substrate (ground material) you should choose whichever one is easiest for you to keep clean and dry. Many people successfully keep their reptiles on newspaper or paper bags. When soiled, the paper can be pulled right out and replaced. Another option is astroturf or some other kind of carpet. This is a little nicer to look at than paper, but is slightly more difficult to keep clean. If you have multiple pieces of carpet, you can simply replace the soiled carpet with the clean carpet. The soiled carpet can then be rinsed and cleaned with a bleach solution. (One part bleach to ten parts water will do.) You should always rinse items thoroughly that have been cleaned with bleach or any detergent.
I do not usually recommend using a partiuclate substrate. That is, sand, gravel, wood chips, or anything similar that your iguana can ingest. Sand, gravel, and wood used as substrate has led to impaction, and the dust from wood chips/mulch can lead to respiratory problems. The problem is that the iguana is enclosed in a very small space with this particulate matter, and due simply to cramped quarters or boredom, iguanas frequently end up eating quite a bit of their substrate (or inhaling it).
Exceptions to the particulate substrate rule:
I only recommend substrate such as cypress bark or mulch (never ever use cedar or pine chips) in very large enclosures. If the iguana spends 99% of its time basking on shelves or branches, and only retreats to the floor to poop, bark/mulch substrate can be satisfactory.
A popular particulate substrate for small cages is rabbit food (essentially alfalfa pellets). These pellets are not harmful to ingest (as long as they are clean!) and some people find them more aesthetically pleasing than carpet or paper. If you use this as substrate, you must be dedicated to scooping out soiled rabbit pellets immediately.
Above all, you must choose a substrate that you are willing and able to keep clean and that is not harmful to your iguana if ingested. Minor cuts or scrapes can become infected if your iguana is living in dirty conditions. Also, the cleaner you keep your iguana cage, the less chance that mites will decide to move in. (See External Parasites section.) If you find that you cannot keep a more exotic substrate such as wood chips clean, you must change your substrate to something easier like carpet or paper.
Iguanas come from hot, humid areas of Mexico, Central and South America. Many places north of Mexico are relatively cool and arid. The high relative humidity is good for your iguana's skin, but it has proven difficult to effectively maintain high-humidity environments for captive iguanas. Not only can it be tricky to raise the humidity to the proper level (iguanas feel right at home when the humidity level reaches 85-95%) but it is difficult to keep such enclosures clean. Hot, humid areas are succeptible to bacterial growth, and with food and feces in such close quarters, the humidity can prove to be dangerous. Subsequently, most iguanas are kept in environments that have low relative humidity, and seem to suffer no adverse effects except perhaps dry skin. This condition may be evident by the appearance and feel of the spines along your iguana's back. When the humidity is high, shedding is accomplished easily, and the dead layer of skin on the spines can be pulled right off without any problem. When the skin is dry, the spines often appear white (due to the dead skin) for long periods of time, and the skin on the scales sometimes comes off in part rather than in whole. Still, this does not seem to be detrimental to iguanas in captivity, and the dry skin condition is preferable to bacterial growth!
If you do wish to try to raise the relative humidity in your iguana's enclosure, there are a couple ways of doing so. If your iguana has a large enclosure, you can simply purchase a humidifier to add moisture to the air. If your iguana lives in a smaller cage, you can add humidity in a few different ways. You can either use a spray bottle to mist the iguana and the cage once or twice a day, or you can place a large bowl full of water in the cage which will evaporate and raise the humidity level. If you choose the water bowl method, you may wish to place a heat lamp above it to speed up evaporation, or placing an under-tank heater underneath that area will create the same effect. To help your iguana with its shedding, you may also soak it in warm water. You can gently rub your iguana's skin to help remove dead skin, but never pull off any skin that is still "stuck" on.
A factor in iguana cage design that is frequently overlooked is ventilation. If your iguana lives in an "open-air" cage that is made out of wire or screen on the sides, ventilation surely will not be a problem for you. Even aquariums with screen lids usually have enough ventilation. Do not, however, use an aquarium with a full hood, such as is used for fish. These will not permit air flow in and out of the aquarium. We have all been in overcrowded subways or buses that were so stuffy that we thought we might suffocate. Now imagine the subway at a temperature of about 90 degrees fahrenheit, probably with food or feces at your feet. Your iguana would not like this scenario any more than you would! So make sure there is an air source in your iguana's enclosure. There are some aquarium-like iguana cages on the market that are glass on the sides and the top, with vents spaced around the sides. These cages seem to have satisfacory ventilation. However, if you have a glass top on your iguana's cage, ultraviolet light will be filtered as it passes through the glass. (See Ultraviolet Light section.) You need to have a cage that is well-ventilated and that is able to pass UV light through its top or sides.
The addition of plants to lizard habitats can be quite aesthetically pleasing. In addition, one might hypothesize that captive iguanas would enjoy the presence of plants, as they live among lush vegetation in their natural environment. But you must remember that plant leaves serve as food for wild iguanas, and iguanas will relish plants as food in captivity as well. In the wild, the consumption of plant life by iguanas is not a problem, as there is well enough of it to go around and one of its purposes is to serve as food for herbivorous animals. Similarly, when plants are added to a cage or when iguanas are exposed to plants in the home, chances are that your iguana will decide to taste-test the local fauna. If the taste is agreeable, your iguana may return to it each day for a snack, leaving the fate of the plant as questionable. Many times, iguanas will chew on plants enough to kill them. They also tend to damage plants when climbing them.
In addition to the chance that the plant might suffer, your iguana's health may suffer as well. The plant leaves might throw off your iguana's nutritional intake if it eats too much of a plant that contains, say, too much phosphorus. (See Calcium and Phosphorus section.) There is also the chance that you may unwittingly offer a plant that is toxic to reptiles. If you choose to expose your iguana to a plant, please refer to Table 3: Toxic Plants. The plants listed are known to be toxic to reptiles. Please keep the plants in the table in mind when decorating your own living space, even if your iguana lives in a cage. It is likely that you will let your iguana out of the cage on occasion, and escape is always a possibility. Always keep an eye on your iguana if you let it out of its cage into a non-iguana-proofed area.
In light of the above information, you may wish to consider purchasing fake plants for iguana cage decoration. If you let your iguana out of its cage or if it shares your living space with you, make sure that any live plants you may have are out of reach, or make sure that your iguana seems to be uninterested in them. In many cases, an occasional bite won't hurt either the plant or animal. But the long term effects can be unfavorable.
The short answer to the question of whether or not you may house multiple iguanas in the same cage or living space is "no". The longer answer is that all iguanas have different personalities and some will get along well and some will not. As juveniles, most iguanas tend to live in harmony amongst one another. Do keep this in mind when you are considering adding another iguana to your pet collection. An apparent "friendship" between juvenile iguanas may turn sour within just a few months as they both mature. Males tend to be the most aggressive and territorial. Adult males frequently quarrel, and male/female groups can also get quite rowdy if the male is interested in mating. Groups of females tend to get along better than groups that contain even one male, but females can be territorial as well and problems might arise. Sometimes iguanas can hurt each other quite badly, so if you are thinking of purchasing more than one iguana you must be prepared to separate them if their situation calls for it. This means being prepared to have two separate cages for them, two separate heating and lighting systems, and two food bowls. If your time, space, or resources will not allow this, I suggest keeping only one iguana. You never know, without experimentation, how your particular iguana will react to another iguana. (See Reproduction section for additional information.)