Feeding a jumping spider

Size the food to the animal, not the calendar. The working rule is that prey should be no longer than the spider’s own body, and for a nervous or freshly moulted spider, rather smaller than that. A jumping spider is an ambush hunter with excellent eyesight and it will simply decline anything it judges to be a bad idea, which is most of the time the right call.

Flightless fruit flies for spiderlings; small crickets, roach nymphs, or blue bottle flies for juveniles and adults. Blue bottles are the reliable favourite — they are the right size for an adult female, they are active enough to trigger a hunt, and they can be bought as pupae and hatched a few at a time, which is far less work than keeping a cricket colony alive.

Two or three feeds a week suits most adults, and a spiderling wants something most days because it is growing fast. Feed until the abdomen is comfortably rounded, not tight and shiny. An overfed jumping spider is a genuine thing and it is worse than a slightly hungry one: a heavy abdomen makes climbing and jumping clumsy, and a bad landing is a real risk.

Take uneaten prey back out, particularly crickets. A cricket left in an enclosure overnight will chew on a resting spider, and will do it to one in a moult with no ability to defend itself.

A spider that refuses food for a few days is usually either about to moult or has had enough. A spider that refuses food for a week, has retreated into a thick silk hammock and has gone still is definitely about to moult. Neither wants to be tempted with a bigger insect.