All spiders are carnivorous, which means they eat a variety of insects and other spiders. Large spiders are able to eat small vertebrates like mice and small birds.
Spiders have a few tricks up their sleeves that help them catch food. One way they catch food is by lying in plants and on the ground and jumping at their prey. Some hunter spiders will go in search of food and others build webs to catch food. Some species of spiders live in silk-lined burrows and wait until prey comes by before jumping out and grabbing it.
Once a spider catches its prey it will inject it with digestive enzymes that essentially liquefy the insect from the inside out. One the insect has started breaking down, the spider will suck it up into its alimentary canal where digestion begins.
Although most of the 35,000 species of spiders eat insects, some have a more diverse diet. Most spiders will not hesitate to cannibalize one another. All spiders prefer live food and large species like tarantulas are powerful enough to take on small birds, lizards, frogs and millipedes.
The largest spider known to exist is the Goliath birdeater tarantula which lives in South America. The Goliath can grow to be 12 inches across, have 1-inch long fangs and eats everything from mice to birds.