Wurmple is targeted by Swellow as prey. This Pokémon will try to resist by pointing the spikes on its rear at the attacking predator. It will weaken the foe by leaking poison from the spikes.
Using the spikes on its rear end, Wurmple peels the bark off trees and feeds on the sap that oozes out. This Pokémon's feet are tipped with suction pads that allow it to cling to glass without slipping.