Tarantulas eat arthropods such as insects and other spiders, and larger species even prey upon small rodents and reptiles. Contrary to its name, the Goliath bird-eating tarantula very rarely consumes birds.
Tarantulas are some of the largest spiders in the world and are capable of consuming large prey. Grasshoppers, large crickets and beetles are common arthropod prey for tarantulas. Female tarantulas sometimes kill and consume a male after mating. Larger species of tarantula hunt vertebrate prey like mice or small lizards. Goliath bird-eating tarantulas actually consume very few birds. These large, burrowing spiders most often prey upon earthworms, as well as invertebrates and rodents. Bird-eating tarantulas prey upon birds only on rare occasions, such as when a young animal falls from a nest.
Tarantulas do not entrap prey with a web like some spiders, but they do produce silk. Tarantulas have poor eyesight; they mainly detect light, dark and movement. To assist in locating prey, tarantulas use their silk to create trip wires. When a prey animal steps on the silk the tarantula discerns its location and grabs the prey with its legs and fangs. Like other spiders, tarantulas inject venom that incapacitates prey through paralysis and also begins predigesting the soft parts of the animal.
Tarantula venom is relatively weak to humans, producing pain similar to or less than a bee sting. However, as with other invertebrate venom, some people exhibit allergic reactions to tarantula venom that are more severe than normal.