Many species possess urtricating hairs that work like porcupine quills to be thrown at predators. The term urtricating means irritating or inflaming. Like other spiders, a cuticle or exoskeleton covers tarantulas. The fine hairs all over the body are called setae. Tarantulas are mygalomorph spiders whose fangs are used to strike downward and pull the prey against the body.
Tarantulas extend their legs using blood pressure rather than muscles.
Water loss creates problems for the tarantula because it lowers its blood pressure which makes walking difficult. Although the tarantula may present a dangerous presence, it has several predators. Predators include the coatimundi, a raccoon relative and, most dangerous to the tarantula, the tarantula hawk wasps. A female wasp paralyzes the tarantula with a sting and then stuffs it into its burrow, where she lays her eggs on its body. The wasp eggs hatch and feed on the still living but paralyzed tarantula.