what do tiny black spiders eat?

Question

i just caught one in my house...so i wanna raise it

Answer 1

Tiny insects. It's hard to feed something that can see tinier insects than we can, it might be better if you verify it's not poisonous and release it and find a larger spider that you can properly provide for.
I've caught tiny geckos and spiders too, and it can be done, feed variety. Moths, butterflies, lacewings, tiny crickets, anything that it can manage. No ants or anything in the true bug family, like squash bugs-they'll squirt something nasty and aren't tasty at all.