Rattlesnakes rattle there "rattles" to warn there predator (the ones that eat the rattlesnakes). If the predator keeps coming, the rattlesnake will jump, bite, and infect there predator.
they hide.......lol jk I have no clueTheir front pair of legs are adapted into spines and have powerful venom.
by their Poisoness tenticles! they sting you!!
Pteradacylus was too small to defend itself. However, it could escape by flying away from a threat.