What are some causes for digging?

[Dragoon]

Hello.
I have a B.emilia baby that is kept on peat with a bark hide. One end is kept damp, the other dry, since I don't know what it wants, humidity-wise.

It's been going under the hide, and digging. It keeps backfilling the water dish (just to tick me off, lol). Yet it does not appear to wish to hide, since I always see it sitting on top of the bark. It isn't nervous, nor does it bolt when disturbed.
Ambients in here are low 80's.
It is eating well.
I'm just wondering what the hollowed out area under the bark should be telling me? What could it want? Heat, cool, humidity, security? what?
D.

[SaIiLdVaEnR]

Burrows are usually made for any one of several reasons. Firstly, they could be burrowing to use it as a way to hunt, they wait down in the burrow for food to come in then SNATCH. Second, to have a cooler area to hide in. Third, exactly that, using it as a hide, and forthly, humidity deeper in the soil is greater, and therefore if they want a higher humidity they will dig.

[Kyle Barker]

they will often do this to shed as well, humidity is much better inside the web...

[OttawaChris]

Thats kinda like asking why a cat licks itself so much... its just what they do! Ok... all smartass remarks aside. Most terrestrial tarantula species are burrowers.

A burrow provides many things to a tarantula... a hiding place from would-be predators... as Sal said it is a great place to set up an ambush... and its also a dark, cool place to hide when its hot.

I reckon your spider dug itself a little hiding place to run to when it feels threatened. I would bet my bottom dollar that your spider would bolt straight into the burrow if you startle it. Also, as Kyle pointed out, they tend to like molting inside a burrow too (for security I am sure)

I have actually noted higher defensive (some prefer to say aggressive) behaviour in tarantulas when they aren't provided with a hide or enough depth to burrow. Its almost as if they know they cant run and hide, so they choose to fight. They also exhibit more signs of stress when they don't have a burrow or a hiding place.

Tip of the day: Nobody should ever use a UTH for a tarantula cage. If a tarantula is too hot, it instinctively burrows deeper... when the heat source is on the bottom that serves only to bring the spider closer to the heat source and many times to its death.

[Dragoon]

Thanks Chris,

I was hoping to ignore this thread and let it slide...since nobody understands what my question really was!

Thanks for the good posts all, I have done a lot of reading, and I do have *some inkling as to why spiders do what they do...my question was regarding my emilia specifically.
It is not close to molting, it has humid substrate, it has a place to hide. I am unfamiliar with the species, but accounts I have read refer to it as a pet 'rock' that usually hangs out in the open.
So, seeing as it burrowed, my best guess is, it was feeling too warm.

Maybe I should move them away from the microwave vent...
D.

[ChokeOnSmoke]

I dont think mexican redlegs need much humidity more like 60 %. I'm not sure if this would cause him to burrow probably not, but you never know........ at least I dont. Check out arachnopets.com I'm sure they have something on B. Emilia