What do tarantulas and snakes have in common?
they are both horrible
Birds, snakes, and rodents mostly avoid tarantulas because they have hairs carrying irritating toxins. The "spider wasp" (Pompilidae ) stings the tarantula and lays its egg or eggs in the spider's abdomen -- once the eggs hatch, the tarantula carcass is used as a food source by the wasp larvae. Native populations of humans eat tarantulas by roasting off the hairs.
Tarantulas in the wild feed on any small animal they can get their fangs into. This includes beetles, crickets and other small insects, right up to rats, birds, frogs and even snakes or other tarantulas. In captivity most are fed on crickets, and once they are big enough, introduced to baby or "pinkie" mice/rats.