There can be different reasons why a tarantula is climbing the glass wall or is always on the glass. In this post, you will find information on why a tarantula is always climbing the wall or why is a tarantula always on the glass.
The main reasons why a tarantula is on the glass are because you have arboreal species, because there is an issue with the substrate in the enclosure, or feeders that are bothering it. A tarantula might also climb the walls because it is simply exploring after a change or can feel changes in barometric pressure.
When making any changes in your tarantula’s cage, make sure to allow at least a week or two after each change. Don’t make multiple changes at the same time, to avoid overwhelming your tarantula. Making one change at a time will also allow you to find the root causing of the climbing (but not always).
Reason 1. Tarantula climbing the glass because you have arboreal species
There are arboreal (living on trees) and terrestrial (ground-dwelling) species of tarantulas. Goliath Pink Toe, for example, is an arboreal species. If you have an arboreal species of tarantula, it will spend its time on top of the cage. On top of the cage, it will make webs and a retreat, and generally spend all of its time there.
If you have an arboreal tarantula, make sure you have a vertical enclosure for it, otherwise it will be too small. An enclosure for an arboreal tarantula should be at least 12-16 inches (30.5-41 cm) high. A terrarium for an arboreal tarantula should be approximately 2.5 times the legspan in length and 2 times the legspan in width. This way, your tarantula will have enough space to climb up.
Having said that, an arboreal tarantula might be climbing the glass because it doesn’t have any other vertical branch to climb on. At least one branch that stands vertically in the center of cage will greatly reduce the climbing and is needed. It will become a space where your tarantula hangs out every day, spins its webs and makes a retreat.
Reason 2. Substrate issues
Another reason why a ground dwelling tarantula is climbing the glass is because it doesn’t like something about the substrate in the tank. The thing is, some tarantulas dislike very fine or soft substrate, for example coconut fiber or sand. If you have fine substrate or one that is too soft, you might try to replace it and see if anything changes.
Another thing that many tarantulas dislike about substrate is wetness. Some tarantulas will not walk on substrate if it’s overly moist. Try to let the substrate dry a bit and see it makes a change. It’s also better to allow the substrate to dry for health reasons. Overly moist substrates might harbor bacteria and fungi and cause health issues in your tarantula.
What is more, make sure that the substrate depth is adequate. That is especially important for obligate burrowers, that naturally burrow in the wild. Even if your tarantula might not burrow too much, you should have enough substrate for your tarantula’s tank in case of falls from heights.
Optimal substrate depth for a ground-dwelling tarantula is approximately 2-4 inches (5-10 cm), however not more than 4″. For a tree-dwelling tarantula, 2-3″ inches of substrate is optimal.
Reason 3. Lack of a hide
If you don’t have a hide in your tarantula’s enclosure, it might wander around a lot and climb the glass trying to look for a corner to hide. Try introducing a hide in your terrestrial tarantula’s enclosure, so it has somewhere to hide when it feels the need to. For a hide, you can use ceramic pots on their side, cork bark piece, logs or a cave like this one.
Make sure that your tarantula can fully fit into a hide. Humidity should also be higher near the retreat, so make sure to check that as well. If you have a hide that tarantula doesn’t use, you can add another one to see if it likes that one better. Arboreal tarantulas also need somewhere to hide, and if you have a branch in the tank, it should have a hole to provide privacy and anchor points for webbing.
You can read more about optimal humidity levels for your tarantula here (new tab).
Reason 4. Your tarantula is exploring the enclosure
If you have recently changed anything in the tank, then it could just be that your tarantula is exploring the tank. Even small changes in the enclosure are a big change for our tarantulas. In this case, there is no need to worry, and your tarantula’s behavior should go back to normal.
Reason 5. Feeders are bothering your tarantula
If your tarantula climbs the glass all the time and doesn’t come down, then it could be because the feeders that are in the tank are bothering it. There could be a chance that you leave the feeders in the tank for too long.
In general, it’s better to remove any uneaten crickets within 24 hours. Another danger of left feeders (crickets and bigger worms, like superworms) is that they can injure your tarantula if it’s entering molt. During a molt, your tarantula becomes very vulnerable and its exoskeleton very soft.
Reason 6. Your tarantula is thirsty
If your tarantula is thirsty, then it might be climbing the walls to look for water. Make sure to always have a dish full of drinking water in the tank. To adjust humidity, you might sometimes overflow a water dish a little, to allow humidity to rise.
Always check humidity levels with a hygrometer that has a probe like this. It is better to have one hygrometer near your tarantula’s hide, and another one on the other side of the tank. Humidity levels should be higher near a retreat, and lower on the other side. Substrate in general should not be wet.
Tarantulas that are thirsty might climb to look for water droplets. While it is important to always have fresh water for your tarantula, it is especially important when your tarantula is approaching or finishing molt. Tarantulas are especially thirsty after they are done with their molt.
Reason 7: Pests in the enclosure
Tarantulas seem to dislike pests and any fungi growth in their enclosures. If there are any bugs or pests, they can irritate your tarantula. For example, bugs like ants are actually dangerous and can bite and chew on your tarantula. Make sure to check whether there is anything in the enclosure that needs removing and cleaning.
Reason 8: Tarantula climbing the glass due to temperature issues
If temperatures in the tank are too high, your tarantula might become restless and start climbing the glass and going around the tank. Make sure that temperatures are not high, as this can be detrimental to your tarantula’s health.
In general, most keepers don’t need to use any supplemental heating devices as room temperatures are optimal. Temperature of around 75-80 F (23.8-26.6 C) is optimal for many tarantula species, however it does differ depending on where your tarantula is from.
Reason 9: Your tarantula is climbing glass because it can feel changes in weather
There is a theory that tarantulas can sense changes in barometric pressure and come out at this time and climb the walls more. This is commonly related to forthcoming rainfall. While this in only a theory, many tarantula keepers say that their tarantulas start coming out and climbing walls more during specific times of the year when weather conditions are involved.
Now that you know possible reasons why a tarantula might be climbing glass, you might review the setup and make some changes a lot the way if necessary. However, sometimes tarantula might climb the walls without any apparent reasons or without anything being wrong.
Make sure to have a tight fitting lid that locks in place to prevent any escapes. Also make sure that the distance between the top of the cage and substrate is not too big, to avoid any injuries in your pet tarantula.
Tarantula can’t climb the glass?
If you have an issue when a tarantula can’t climb the glass or stick to glass, then it can be very frustrating and heartbreaking to see.
Tarantulas have special sensory bristle hairs (setae) on pads of their legs that help them stick to smooth surfaces, and are called scopulae. Sometimes, a tarantula might have damaged hairs on legs that help it stick to the glass, making it not able to climb temporarily. These hairs should be replaced with the next molt.
However, sometimes, a cause might be a parasitic infestation in the tank, when parasites attack a tarantula and block its mouth opening, and it clean its pads with its mouth.
If it cannot clean its pads anymore, they stop sticking. Make sure your tarantula is not infected and sick. If it looks healthy, its pads could be clogged with substrate and other waste, making it hard to stick to smooth surface.
If your tarantula can’t climb or stick to glass, you need to place a piece of cork bark or something similar like pieces of wood branches. This way, your tarantula can use its claws to climb. It is important to provide something for climbing, because tarantulas get very stressed if they can’t climb. Stress can lead to reduced appetite and even death. Hopefully with the next shed, your tarantula will be able to climb again.
If you would like to learn more about tarantula care, please see this page.