Fossorial Tarantulas Enclosure Guide

Fossorial tarantulas are not complicated pets, but there are particular needs you need to meet for them to live a healthy and happy life. Keeping a tarantula in a suitable enclosure is one aspect, and getting it wrong could hurt them.

A fossorial tarantula should not be kept in a traditional cage. They require a terrarium or another deep enclosure with lots of substrate to burrow in. The walls of the enclosures should be safe for tarantulas to walk on, and there should not be a big distance between the top of the enclosure and the substrate. 

Finding a suitable enclosure for your first fossorial tarantula is critical. Selecting the wrong one can be detrimental to their health and could lead to accidental harm or death to the tarantula.

What Type of  Enclosure does a Fossorial Tarantula Need?

Fossorial tarantulas require a deep terrarium or aquarium enclosure to allow for a lot of substrate. The enclosure should have tarantula safe walls with lots of ventilation. Fossorial tarantula enclosures must allow for a lot of burrowing.

Here are the best tarantula safe types of enclosures:

  • Glass Tank – However, these are often built for arboreal tarantulas, which means they might not be deep enough for a fossorial tarantula.
  • Aquarium Tank – While an aquarium tank is suitable, these can be too large depending on the tarantula, and they don’t have a tarantula proof lid. Aquarium tanks will also need to have ventilation added.
  • Plastic Tank – These are often sold for smaller tarantulas and terrestrial species but can be adapted for fossorial tarantulas.
  • Acrylic Tank – Often found in smaller sizes for spiderlings and young tarantulas or arboreal species. However, the tall variants can also be suitable for fossorial tarantulas.
  • Plastic Containers – Plastic stack boxes are commonly used by keepers with many tarantulas. These boxes are easy to adapt to a tarantula and are cheap to buy in bulk. Small plastic containers such as deli cups are commonly used for spiderlings. They can also be deep enough for a fossorial tarantula.

Arboreal tarantula enclosure can work well for fossorial species as well. If the enclosure is tall and has an entry point into the enclosure on the lid, it will be perfect for a fossorial species. Tall enclosures allow for more substrate, which will make a fossorial tarantula happy.

What Size should a Fossorial Tarantula Enclosure Be?

A fossorial tarantula needs an enclosure that should be at least three times the width of the leg span. The distance from the substrate to the top of the enclosure is ideal at around two times their leg span. Any higher than this could put the tarantula at risk of death if they climb to the top and fall.

A fossorial tarantula needs an enclosure with a lot of substrate. At least 20cm (8 inches) is necessary for them to be comfortable inside the enclosure. The amount of substrate needs to be scaled with the size of the tarantula. If the enclosure allows for more substrate, the tarantula will burrow deeper.

Can I keep my Tarantula in an enclosure with Netting or Wire Mesh?

Netting and wire mesh are dangerous for all tarantulas. Their retractable claws can get stuck on netting and wire mesh. Enclosures with a mesh top are hazardous as the tarantula could be left dangling from it after getting a leg stuck.

In addition to them getting stuck, these materials contain too much ventilation. The enclosure will dry out or be influenced by the room environment more than expected. This means the enclosure could become very dry if it’s hot where you live, or the enclosure might gain more humidity depending on the local weather and the room they are being kept in. Using netting or a wire mesh makes it harder to control the environment inside the enclosure.

How much Substrate does a Fossorial Tarantula Need?

There is no perfect amount of substrate for a fossorial tarantula, but at least 20cm (8 inches) would be ideal. The tarantula will most likely dig to the bottom, so it’s best to add as much substrate as possible into the enclosure.

The amount of substrate depends on the size of the tarantula. Young tarantulas don’t need as much substrate as adults or larger tarantulas. Fossorial tarantulas will spend almost all their time inside their burrow, making it challenging to rehouse them when they outgrow the enclosure.

What is the Best Substrate for a Fossorial Tarantula?

Fossorial tarantulas need a substrate that allows for a lot of burrowing. Burrowing friendly substrate includes topsoil, peat moss and pre-made fossorial tarantula substrate mixes. Most fossorial species will line their burrows with silk, strengthening them against cave-ins.

Coco fiber is commonly recommended for tarantulas, but it’s not ideal for fossorial species. This substrate will harden over time, making it more difficult for a burrowing tarantula to dig through. This fiber is also known to have a higher risk of causing burrows to collapse. However, it’s often added into substrate mixes for fossorial tarantulas in small amounts.

Pre-made options exist, which have been carefully created to provide tarantulas with whatever they need. Some keepers will make their own substrate mixes using topsoil, coco fiber, peat moss and vermiculite. It’s important to remember that a fossorial tarantula also has specific humidity needs.

How to make a Suitable Fossorial Tarantula Enclosure

An enclosure for a fossorial tarantula needs to be deep with an access point on the top for you to use. The enclosure must be well ventilated and requires at least 20cm (8 inches) of substrate. It needs to have a drinking bowl, and the enclosure cannot be built from mesh or netting.

A fossorial tarantula needs a deep enclosure that allows for at least 20cm (8 inches) of substrate though depending on the size of the tarantula, they might need more or less. The enclosure should be well ventilated before adding substrate. Tarantula enclosures are usually sold with ventilation built into them. 

Fossorial tarantulas need a substrate suitable for deep burrows and provide the proper humidity. The best substrate options for a fossorial tarantula include topsoil, peat moss and combination mixes. Coco fiber can work, but it can be difficult for your tarantula to burrow through when it hardens.

After this, they just need a water bowl. A hide is not required for fossorial tarantulas, but more anchor points for webbing such as fake plants are often appreciated.

While there are no specific guidelines for creating a fossorial tarantula enclosure, many popular YouTubers such as Tarantula Collective (https://youtu.be/N0m0q51MAHg) are valuable information sources. They explain why specific enclosures are better for fossorial species and how they design their setups.

What Happens if a Fossorial Tarantula doesn’t have room to Burow?

Fossorial tarantulas instinctively need to burrow deep into the substrate. They feel most comfortable underground and will block off the entrance when they want privacy. Being unable to do this causes them distress, leading to more defensive behaviour.

Even if there is a low amount of substrate, the fossorial tarantula will still try to dig down as much as possible to feel safe. If they can’t feel safe inside the enclosure, they will become more defensive as they don’t have a place to hide when needed. Adding a hide may help give them more cover when they dig down.

Potential signs of stress and distress due to lack of burrowing space include:

  • Threat posing and striking at you
  • Kicking urticating hairs / Bald patch on their abdomen
  • Abnormally high activity such as pacing and climbing
  • Hiding behind their legs
    • Some tarantulas will curl their legs over their head to hide. This is not ‘cute’ behaviour; it means the tarantula is scared!
  • Excessive climbing
  • Refusing food

Every tarantula is different. Some may not react as strongly as others, and others might display behaviours not listed here if they are stressed. Tarantulas might even show these behaviours when they aren’t stressed, especially refusing food.

While sometimes tempting to only provide a small amount of substrate for a fossorial species, it’s best to give them as much as possible. The tarantula will never feel safe if they cannot burrow deep enough. The only time they should not be given as much substrate as possible is they need to be held in a temporary enclosure for a short time.

Will a Fossorial Tarantula be distressed if they can’t Burrow?

Fossorial tarantulas may not show stress or distress in an obvious way. If the tarantula cannot burrow, they may become more defensive, changing their behaviour. Behaviour changes include performing threat poses, climbing the walls and hiding behind their legs.

If a fossorial tarantula feels stressed, uncomfortable, and unhappy, they will act differently from normal. These are some of the potential behaviours they might display when stressed:

  • Threat posing and striking at you
  • Kicking urticating hairs / Bald patch on their abdomen
  • Abnormally high activity such as pacing and climbing
  • Hiding behind their legs
    • Some tarantulas will curl their legs over their head to hide. This is not ‘cute’ behaviour; it means the tarantula is scared!
  • Excessive climbing
  • Refusing food

Tarantulas may not react as expected if they are stressed. Don’t assume the above list is the only behaviour a tarantula might display if they are stressed. Tarantulas respond in different ways when stressed or unhappy with their living conditions. It’s also normal for tarantula’s to refuse food for months without being stressed.

Is it Safe for a Fossorial Tarantula to not be able to Burrow?

Fossorial tarantulas will not feel safe if they are unable to burrow. The tarantula’s behaviour will change if they cannot burrow as deep into the substrate as they need. Behaviour changes can include being more defensive than usual, climbing, hiding behind their legs, etc.

While most of the behaviour will not lead to the death of the tarantula, if they start to climb more, it could seriously harm them. Fossorial tarantulas are not good climbers, and if a tarantula falls, it may rupture their abdomen leading to their death. If there isn’t enough substrate inside the enclosure, there will be a greater distance between the top of the enclosure and the substrate, which increases the chance of death.

If the fossorial tarantula cannot burrow, they may also refuse food or perform more defensive behaviour towards you. Defensive behaviour such as threat posing and striking might not kill them, but if you react badly to this, you could injure or kill them by accident. 

Potential stress behaviour from a fossorial tarantula due to lack of burrowing space includes:

  • Threat posing and striking at you
  • Kicking urticating hairs / Bald patch on their abdomen
  • Abnormally high activity such as pacing and climbing
  • Hiding behind their legs
    • Some tarantulas will curl their legs over their head to hide. This is not ‘cute’ behaviour; it means the tarantula is scared!
  • Excessive climbing
  • Refusing food

Tarantulas react to stress differently, so they might only display one of these behaviours or none of them. Each individual will respond in their own way to different potential stressors. Others might even do these things without being stressed!

Will Less Substrate Make my Fossorial Tarantula more Visible?

A fossorial tarantula enclosure with less substrate might make them more visible, but this is terrible animal husbandry. It’s not good for the tarantula to give a small amount of substrate. A low amount of substrate will make the tarantula stressed and unhappy.

For the tarantula to be happy, they need a lot of substrate. Fossorial tarantulas need to be able to dig as much as possible to create a place they can feel safe in. If they can’t feel safe, they will display different behaviour than normal.

Potential stress behaviour from a fossorial tarantula due to lack of burrowing space includes:

  • Threat posing and striking at you
  • Kicking urticating hairs / Bald patch on their abdomen
  • Abnormally high activity such as pacing and climbing
  • Hiding behind their legs
    • Some tarantulas will curl their legs over their head to hide. This is not ‘cute’ behaviour; it means the tarantula is scared!
  • Excessive climbing
  • Refusing food

Tarantulas will react differently to each situation, and there’s no guarantee they will show any of these behaviours. Some fossorial tarantulas may only show one of the above behaviours or none of them. Refusing food is typical for all tarantulas, even without them being stressed.

Conclusion

Fossorial tarantulas should only be kept in deep enclosures that allow for a lot of substrate to burrow as much as they want. Like all tarantula enclosures, they need to be well ventilated and cannot feature any mesh or netting. While fossorial tarantulas don’t usually climb, an enclosure with netting could still be dangerous, especially if the enclosure lacks substrate. Not including enough substrate in the enclosure will lead to behaviour changes and a stressed tarantula.

Written by:

Stuart

Stuart is the editor of SpiderAdvice.