It is sometimes said that hogs are not harmed by the bites of poisonous snakes, and this is more or less true.
Strictly speaking, hogs are not immune to snake venom, but they have something that is almost as good as immunity-a thick layer of fat just beneath the skin. The venom is probably deposited in this layer and absorbed so slowly that no harm results.
The hedgehog, however, does appear to have actual immunity to the bites of some snakes. It has been known to kill and eat the venomous European adder without suffering any ill effects if bitten during the process.
But immunity is not the only weapon at its disposal.
Observers have seen a hedgehog cautiously approach a snake, make a sudden snap and then quickly turn its back. The snake, if it is still able to move, usually responds by striking fiercely, only to find that its bite falls harmlessly and unpleasantly upon the hedgehog’s sharp quills.