Prey handling and feeding
After biting a trapped insect, an Orb Weaver securely wraps it in bands of silk. Photo: B Rudman © Australian Museum.
A flower spider, Thomisus spectabilis, eating a honey bee, which will be left as an almost intact, dry husk. Photo: © Densey Clyne.
Spiders immobilise their prey in two ways - by biting and injecting paralysing venom, and by silk swathing and wrapping. Most hunting spiders simply grab and hold their prey in the pedipalps and front legs, while biting it. Many web builders use bands of swathing silk to throw over or wrap around the entangled prey, often before biting it, although larger web builders tend to bite first. Securely silk wrapped prey is sometimes stored in the web to be eaten later. Spider venoms affect the nervous systems of arthropod prey and interfere with nerve-muscle impulse transmission, resulting in paralysis. Venom also helps with the chemical break down of prey tissues. When feeding the spider regurgitates enzyme rich stomach fluids over and into its prey. This external digestion by venom and stomach chemicals, often aided by the grinding, masticating action of the fangs and toothed jaw bases and maxillae, reduces the prey's body and tissues to a chitinous soup. The liquid is sucked up through the spider's tube-like mouth, aided by the action of the pumping stomach, leaving the hard parts behind. Spiders like flower spiders (Thomisidae) inject digestive fluids into the bitten prey and suck out its liquefied internal tissues, leaving an almost intact body husk behind.
