Ventilation Below Substrate

It seems to be a consensus here that vent holes in an enclosure that are below the substrate are a waste. However, with deep substrate and a burrowing T, is this still the case? Some of my containers have a few vent holes below the substrate, especially for those burrowers that go right to the bottom. This way there is still some ventilation for them. Is this, indeed, a "waste" or not such a bad idea? I think it also allows some air to get into the substrate, along the lines of holes in the bottom/sides of a flower pot, to prevent mold or other problems.

Medusa said:

It seems to be a consensus here that vent holes in an enclosure that are below the substrate are a waste. However, with deep substrate and a burrowing T, is this still the case? Some of my containers have a few vent holes below the substrate, especially for those burrowers that go right to the bottom. This way there is still some ventilation for them. Is this, indeed, a "waste" or not such a bad idea? I think it also allows some air to get into the substrate, along the lines of holes in the bottom/sides of a flower pot, to prevent mold or other problems.

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I don't think its of any real help. I also doubt it would hurt but consider....When a t burrows in the wild, there's no vent holes aside from the exit(s) and they don't have sides, which can create a slight amount of space....and some of these burrows are 5, 10, or as deep as 20 feet (I think the deepest recorded burrow was H. gigas at 22') below solid hard packed earth, and they seem to like it. They even cover the entrance at times, further reducing airflow. It wouldn't surprise me if burrowers actually preferred low airflow within the burrow. Mine catches any breeze and its at the bottom in a flash. I really want more burrowers, I find their lifestyle interesting.

Did you say feet? I have heard the 22' thing about H. gigas but always assumed inches. You are saying they have had a 22 foot burrow?? That is very interesting!

22"= 22 inches

22'=22 feet

yes, 22 feet deep.

cold blood said:

I don't think its of any real help. I also doubt it would hurt but consider....When a t burrows in the wild, there's no vent holes aside from the exit(s)...

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But when burrowing in the wild they aren't up against plastic walls...I'm just talking a couple small holes near the bottom. Might still do it but I think it's an interesting consideration.

Medusa,

Ventilation holes along the bottom edge of the container is a good idea if you are housing an obligate burrower and I have used them for all of mine over the years. I'm beginning to experiment with this with taxa such as Aphonopelma and Brachypelma as opposed to tropical Asian taxa such as Haplopelma. For it's purpose though, they are best described as "water drainage holes." Water is best provided to a burrower by pouring it down the burrow or watering the substrate/ soil to where the water drains down to the bottom then letting it dry out and watering again in the same way. The tarantulas will get its water from the small pools that collect at the bottom, from the soil, and from its food. I've been fortunate when doing this myself to see my tarantulas drink as the water reaches the burrow chamber as I was dripping water into the burrow opening. It's really neat to watch.

When watering the soil, the excess water needs to drain away so the spider is sitting in a flooded burrow. Soil types and mixtures are also important for burrowers in order to provide adequate water drainage AND aeration. As you might be thinking, it starting to sound like I am describing a way to plant a spider. I have used a lot of knowledge from the horticulture hobby in order to provide my burrowing tarantulas a better, more natural captive habitat. I find the concepts of housing a tarantula and potting a plant have a lot in common.

You were correct in your last post that while burrowing in the wild, they are not up against plastic walls. In the wild, the soil allows for drainage and aeration and if for some reason the ground becomes unsuitable, the tarantula can pick up and move somewhere else. Not the case in captivity.

There is an article written by Martin Huber and Volker von Wirth in an issue of the British Tarantula Society journal that describes a method for housing burrowing tarantulas which uses drainage holes. If you send me your e-mail address in a PM, I will gladly send it to you since it describes exactly what you are inquiring about.

- Lonnie

Yeah, I always assumed it was a typo when they said that. Wow, that is crazy!

cold blood said:

....and some of these burrows are 5, 10, or as deep as 20 feet (I think the deepest recorded burrow was H. gigas at 22')

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Call me skeptical, but 22 feet deep seems rather exaggerated and I wouldn't believe that unless I saw proof of it. If I think about how deep that would be which would be about the depth of two of my rooms stacked on top of one another than that sounds ludicrous. Besides, think of the mound of soil at the surface that the spider would create excavating that much. If that H. gigas burrow depth of 22 feet is actually recorded, than that must mean there is documentation on it somewhere. 22 inches, almost 2 feet, sounds right though.

See I think 22 inches sounds like a ridiculously shallow borrow for a t with burrowing capabilities, especially considering they have 5, 10, or in the case of some like P. muticus 20+ years to burrow. I'd bet most burrowers would quickly burrow to the bottom of an enclosure 2 feet deep. It seems no matter how deep I make the sub, the burrows ALWAYS end where the enclosure ends, and I'm talking brachy's and grammy's, not spectacular diggers like baboons. My ezendami was at the bottom in 4 inches of sub within an hour, and it was only an inch at the time.

For fossorial species, you can put drainage holes at the bottom of the substrate so when you put water in the substrate, extra moisture can drain out. Beyond that, if you've packed in your substrate properly, the vent holes wouldn't do anything.

The other thing to consider about depth is predators in the native area. Something like a hyena or honey badger would get a few feet down without breaking a sweat, t's in that region (known for serious burrowing species)would be easy pickin's for predators at a mere foot or two.

AphonopelmaTX said:

Call me skeptical, but 22 feet deep seems rather exaggerated and I wouldn't believe that unless I saw proof of it.

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It's been documented for Hysterocrates (which also swim, and kill prey and feed it to their young). Keep an open mind with tarantulas. There's very few things that apply across-the-board with them.

If you have the paper that documents it, can you link it? Ever since that was brought up a few days ago, I have searched to no avail for a scientific source for a 22' burrow.

Edit: while I don't have photo proof (I know - it didn't happen), I had an H gigas that I had in a 15 gallan tank filled to around 3" below the lid with peat. She burrow down and wrapped around the enclosure which I measured at around 36" from entrance to her final "chamber". So deep burrows I don't doubt, but i'd like to read the paper that sourced it.

I always put ventilation holes around the substrate. I think it's helpful, but I have no proof for or against. In the wild, soil isn't a solid like a brick or a piece of steel.

viper69 said:

In the wild, soil isn't a solid like a brick or a piece of steel.

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Just a thought;


When anything is "buried alive", surrounded by dirt, it dies. Soil, dirt, or whatever may not be like steel, but it certainly does not provide enough passage of air to keep living things alive. T's require little in the way of oxygen (compared to mammals), so it would take a significant amount of time for a t to use up all the available o2 in a burrow, and the bigger the burrow, obviously the longer that would take. Even worms come to the surface.

cold blood said:

Just a thought;


When anything is "buried alive", surrounded by dirt, it dies. Soil, dirt, or whatever may not be like steel, but it certainly does not provide enough passage of air to keep living things alive. T's require little in the way of oxygen (compared to mammals), so it would take a significant amount of time for a t to use up all the available o2 in a burrow, and the bigger the burrow, obviously the longer that would take. Even worms come to the surface.

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Another ELITIST answer from the Peanut Gallery! :biggrin:


Nah, all I meant was I put holes below the substrate because in nature the soil isn't solid, so it does get some air a bit. How far down it penetrates I really don't know. Plus, personally I have been known to over-mist at times, and having holes below the sub let things dry faster. Can't have a Noah's Ark for my 8 legged wonders!

cold blood said:

Hahaha, I didn't even use the fancy colored bold print.

perfect grammar btw...nice!

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Well you know those losers that use bold colored fancy font are just attention seekers! :sarcasm: