Tool up, America! Today I'm on the pulpit about self-reliance and herptetoculture. I beleeeeve that we who keep specialty animals are best served by owning and knowing how to use at least a few basic power tools. Table saw or hand-held circular saw, router, drill, preferably cordless (much more maneuverable) and the blades and bits to go with. Some clamps, including squeezy hand clamps and a few pipe clamps. With this small arsenal of tools, no keeper need fear installing housing which provides excellent quality of life.
Or, you could have a friend who does this sort of work or decent millwright handy.
A long time ago, far, far away--wait--that's already taken. OK, suffice to say I had not given much thought to the issue of heat creep in reptile cages until a few years ago. My herps had basking areas adjusted as needed to keep them healthy but I did not appreciate just how effectively herps harvest heat and keep it internally while using it to run around after leaving the basking site. Closed cages with no forced venting allow heat to creep from the basking area to the rest of the cage, and may result in animals having no place to escape the warmth, which can make them uncomfortable.
One day, I was visiting the Arizona-Sonora Desert Museum and one of the keepers was showing me their hatchling horned lizards. He pointed out that the hatchlings had not thrived until the keepers hit on the idea of making a hole in the cage wall on the end with the basking light and fan-venting the heated column of air under the light, pulling the hot air out of the cage and leaving only the light's radiance to carry heat to the animals, as in Nature. Voila! The hatchlings improved at once. Aha! says I--ze secret, she is revealed. I sprang to my car, bolted home and designed the first of many home built enclosures incorporating fan-vented basking areas, with good results. The behavior of my captive coachwhips and lizards changed to resemble the behavior of wild animals more than it had, and they seemed to improve in attitude. Too much human projecting? Maybe, but they did look a tad happier, and I'm sticking to it.
Now, Eastern and Texas Indigos are serious heliotherms, harvesting radiant heat from sunlight even on overcast days. Some may say that tropical snakes use a greater proportion of environmental heat from lingering heat in the air, or even warmth from decaying vegetation, of which there is no shortage in the tropics, but certainly the Black Milk Snake, the only tri-color milk snake to turn completely black when grown, chiefly harvests radiant heat from sunlight even on foggy days in its cloud-forest habitat. As an aside, the Black Milk is an extraordinary animal and an essential living example of several critical learnings about reptiles and life in general.
But back to Indigos; American Indigos do not harvest heat from substrate as much as tropical herps do, but they are still tropical in origin. The Easterns are nice and black, to capture as much radiant heat as they need, but they don’t like to be overheated, as in a cage that is allowed to get warm all over with no place to escape the heat. The answer? Fan venting the heat lamp.
Axial fans are those little boxy fans that you have inside your computer, or in the stove vent, or in some vent shaft or other. They are the fans of choice when building the home snake cage, and they can change the life of captives in a twinkling. Let’s build an Indie cage using an axial fan to vent the heat from the heat light at one end, shall we? Ooo—lets!
Okay, okay cut to the premier Indigo cage design. Off to Home Depot for some half-inch Birch Plywood, a sheet of Melamine-coated one-eighth thick hardboard, sometimes called tileboard, some window screen and a few sheets of something called textured tileboard, which is a slightly flexible plastic sheet four feet by eight feet. After you see how the whole thing fits together you could substitute formica for the tileboard.
The carcass of the cage is the plywood. Decide which end will have the heat bulb. Cut the top and back to your specifications, likely dictated by available space. As I love Indigos and advocate spacious living quarters for most herps, I hope you have six feet of linear space to allocate for a cage for one adult Dry.
The larger the heat bulb, the greater the heat it puts out, even if it’s the same wattage as a smaller bulb. You can buy a lamp-sized 40 watt bulb but you will get more heat and wider coverage from an outdoor 40-watt flood bulb. If I were building this cage, I’d make it tall enough to use the outdoor bulb, which is larger. I’d make the cage about 18 inches tall.
The floor of the cage is covered with the Melamine tileboard, which is smooth and easy to clean. If you have space under the cage you could even install a floor drain for hosing the cage down from time to time. On smaller cages I use the one-eighth thick sheet with no support, just affixed to the bottom of the cage, but this is a large cage, so you might want to laminate the tileboard to a sheet of half-inch plywood for support. That will add weight so think about where the cage will rest.
Once you have decided on dimensions for the rest of the cage, cut the sides, back and top. Using your router, cut a circular hole in both ends to match the size of the opening in the axial fan. You will mount the fan over the hole adjacent to the heat bulb and the hole at the far end will allow air to flow into the cage to replace the air vented from under the heat lamp by the fan. To cut circles, first carefully make a circle in a piece of scrap, which will guide the ball bearing on the bit of the router. Drill through the piece you want to make the final hole in, clamp it to the template and to a sturdy bench, and cut the holes in both ends of the cage. Do bear in mind that this is done before any assembly—at this juncture, you are working with flat pieces which have been cut to size on the table saw.
Now you have a bottom covered with Melamine, two sides with vent holes and a back piece. With less messy snakes, it makes sense to just varnish the interior of the cage but Indies are crap hoses, which is why I suggested the tileboard. It’s easily cleaned and sterilized if needed.
Cut the tileboard to fit over the ends and back of the cage. Use contact cement to attach the fitted tileboard to the back panel. When fitting the tileboard to the end panels, clamp or cement only the edge of the cut tileboard to the panels, so you can route the hole in the tileboard over the hole in the plywood, and still peel the tileboard back to insert a piece of window screen over the hole between the plywood and the tileboard before you contact cement the rest of the sheet of tileboard into place. Leave enough screen around the edges of the hole to be firmly trapped between the tileboard and the plywood so the screen can’t be pushed out.
Now you have two end panels laminated with textured tileboard, each with a screened hole in it, plus a back panel covered with textured tileboard, and a bottom panel covered with smooth Melamine. The top of the cage is cut to the same size as the bottom, and fitted with electrical fixtures. It’s unlikely the ceiling will become soiled, but if you like, it won’t hurt to seal it with a coat of varnish before installing the electrical fixtures.
Near one end of the top, the end adjacent to the side wall with the vent fan, mount a porcelain ceiling socket to hold the heat bulb. The wire to the socket passes through a hole in the panel and the flared base of the socket covers the hole the wires pass through. If this were my Indigo cage, I would mount an economy 15-watt fluorescent fixture near to the heat bulb, to hold a UV fluorescent bulb which would be on for a few hours in the morning only, the same hours when the snake was collecting heat from the heat bulb. I know that conventional wisdom claims that snakes do not require UV light, but I find that they do better with it than without, and all my snakes get UV light in the manner I describe here. Just a few hours each morning—maybe three hours. The rest of the day, the UV bulb is off (it’s on a separate timer from the rest of the cage electrical) but the fan, heat bulb, and general illumination bulbs stay on for the remainder of the photoperiod.
For such a long cage, I’d mount two more 15-watt fixtures further along toward the far end, one at the front aimed back into the cage and one at the rear aimed forward, to cover the cage floor with light. To mount economical 15-watt bulb fixtures on the ceiling of the cage, I drill a hole large enough to pass the plug through, then position the fixture over the hole, forcing the wire behind the fixture, then screw the fixture to the cage ceiling, trapping the wire behind it with the plug end passing out through the hole in the cage ceiling. Pull the wire tight as you screw down the fixture to avoid leaving a loop of wire to tempt your snake to crawl through it.
For those lights, I use Lumichrome bulbs, which have a Color Rendering Index of 98 and a visual temperature of 6500 Kelvin, as close to sunlight as any bulb available. Good for the snakes and good for the keeper. To purchase Lumichrome bulbs, search Lumiram on the Internet and visit the websites of the vendors they recommend.
Assemble the cage by connecting the base to the sides and back. It might be a good idea to seal the seams around the floor and where the sides and back meet with a bead of Silicone sealant. I also make a litter dam by installing a cleat (when I do it, the cleat is usually a hard wood like oak, and attached by driving screws up through the floor into the cleat) inside the cage, along the bottom inside the front behind where the door will close. This cleat is varnished to seal it, and silicone is applied to the inside seam where the cleat meets the Melamine floor, waterproofing the entire cage floor.
You can make the front of your cage close using any style of closure you like. Sliding glass works well, but you need to be sure you have room for the front pane to slide out to one side or the other. Some sliding closure cages use overlapping panes but snakes are prone to forcing their snouts into the small space between the panes, and months of this behavior can result in permanent snout deformities. Indigos are particularly prone to this sort of obsessive behavior. You can also make a door by framing a panel of acrylic with a wood frame that is hinged at the top or bottom and secured by a latch or cylinder lock on the side opposite the hinge. The door is large enough to cover the front of the cage to its exterior dimensions, so if you extend the clear viewing panel out to the edges of the door you will seal the door frame against moisture.
When you assemble your cage, you will end up with a cage that has all interior surfaces which contact the snake sealed behind plastic or Melamine. When the cage is finished, one end will have an incandescent bulb providing radiant heat to any snake basking under it, with a fan venting the air column under the bulb through an adjacent vent to prevent the bulb from warming the air in the cage. I mount my axial fans on the outside of the cage and install the optional blade guard, available where the fan was purchased. I buy my axial fans at Grainger, which sells several different size/power axial fans. The electrical cords that the fans use are also available there, and are sold separately, as are the blade guards. With an axial fan mounted over the vent under the heat lamp, the cage never gets hot and the snake can get away from the warmth of the bulb simply by moving out from under it. The whole cage uses an axial fan, an incandescent bulb, and three fluorescent fixtures including the one for UV light at the end where the snake will be basking under the heat bulb in the early part of the day.
Once the cage is running, a snake can capture heat when it wakes up and spend some time being active without being stuck in a hot cage with no escape. Cooler air from the room will be pulled in to the passive vent at the end away from the fan to replace the air evacuated from under the heat bulb, and the snake will be able to harvest heat via radiant energy, as in the wild. The behavior and overall health of my coachwhips, racers and other dedicated heliotherms improved when I started fan venting the heated column of air under the basking bulb, and I’m sold, sold, sold on the system.
As for owning tools and being able to construct custom cages to fit your unique situation, I say there is no substitute. Be careful and keep inexperienced woodworkers away from power tools—no need to risk more grief than pleasure from an excellent hobby. Plus, the ability to produce top-quality housing for the wonderful creatures in our care, as needed and at our own pace, adds freedom to our development schedules and quality to the lives of our captives. Viva Liberty! Viva quality! Viva—shutting up.
