Lepidopteran species are soft bodied, fragile, and almost defenseless, while the immature stages move slowly or are immobile, hence all stages are exposed to predation. Adult butterflies and moths are preyed upon by birds, bats, lizards, amphibians, dragonflies, and spiders. One spider species, "Argiope argentata", eats butterflies and moths and exhibits a long bite when preying on them rather than wrapping them in silk first. This is theorized to serve as an immobilization tactic. Caterpillars and pupae fall prey not only to birds, but also to invertebrate predators and small mammals, as well as fungi and bacteria. Parasitoid and parasitic wasps and flies may lay eggs in the caterpillar, which eventually kill it as they hatch inside its body and eat its tissues. Insect-eating birds are probably the largest predators. Lepidoptera, especially the immature stages, are an ecologically important food to many insectivorous birds, such as the great tit in Europe.