Ugh! When I lived in the desert, ants (not fire ants) got into a banded gecko cage after his mealworms primarily, but they killed him too. Only a couple of
ants were on him, I couldn't believe my eyes. Ants are scary, & relentless too.
I discovered a product (sold in CA) that both killed & repelled ants safely & effectively (supposed to be safe for pets, kids, kitchen etc- though I'm sure they
didn't mean "snakes" when they said "pets"). Anyway, it was a yummy smelling spray that contained wintergreen & rosemary oils. Killed them AND they didn't
return. Can't recall product name & couldn't find it afterward, but searching natural ways to kill ants may help you. There's a list of alternative things to try.
Such as https://homeguides.sfgate.com/recipe...ide-81790.html
You might also try using diatomaceous earth...also should be safe for snakes & all...read up (fast)
Good luck, let us know what helps? (I would think that 'PAM' would kill them too?)