A wonderful place for the spiders to hang out and eat the cockroaches that also live there, feasting on tortoise scats commonly dropped right there.
Black widows are one of the common occupants of wild tortoise burrows. They are timid, and if you try to swat one you will see how very fast they retreat at the slightest vibration of the web. If you put your hand in a tortoise burrow, watch out for the spider that may be hanging near the roof. If given half a chance, it will escape instead of defending itself because you came too close.
Do not use poison in any form. There is no need and tortoises are very sensitive to such chemicals. Males are less than half the size of the females, have a smaller abdomen, are tan with light-banded legs and body and, like the females, hang upside down in their messy-looking webs. The hour glass-like figure on the underside of the abdomen is not bright red but is obvious. The males have venom but, like the females, seldom use it unless cornered or killing to eat.