The diet of a spider varies depending on its type. Web-building spiders, for example, eat flying insects, including butterflies, moths, and flies that get trapped in their web. Hunting spiders, on the other hand, conceal themselves using camouflage and kill their prey when it comes to them. These spiders usually prey on insects such as crickets, beetles, and grasshoppers. Larger hunting species, including the huntsman spiders, kill lizards and frogs. Most spiders like feeding on prey that has been recently killed.
Most spider species cannot digest plant cellulose and are exclusively carnivorous. A few species, however, primarily belonging to the family of jumping spiders such as the recently discovered Bagheera kiplingi feed on the sap, pollen, and nectar of Acacia tree.
Spiders, being predators, feed on a variety of insect pests such as bed bugs, ants, and mosquitoes. Not all spider species will eat these insects, though. Some of the species that catch and eat ants include the Lynx Spider, Black Widow, and Jumping Spider. Cellar Spiders, on the other hand, paralyze bed bugs with their venom and eat them. Orb-weaver spiders usually eat flying insects such as mosquitoes.
Spiders also need to drink water. Most of them drink from water droplets on the ground or vegetation or from the dew condensed on their web. House spiders usually get water from leaky faucets or the kitchen sink.
After hatching from their eggs, the spiderlings eat their siblings for the first two to three days. Then they usually feed on larvae of flies or gnats. In some species, such as Stegodyphus dumicola, the female spiders are eaten alive by their babies. This behavior is called matriphagy.
Spiders usually do not take solid food directly, but they inject venom into their prey’s body using the fangs. The fluid does not just contain neurotoxins but also digestive enzymes that help in liquefying the prey’s internal organs and tissues while leaving the exoskeleton pretty much intact. Then they suck the liquefied parts of the prey through the jaws and into their stomach.