Keeping a jumping spider

A jumping spider is a small, dry, warm animal that hunts by sight. Almost everything it needs follows from those four words. It wants room temperature, not a heat mat; it wants humidity low enough that its enclosure dries out between mistings; it wants light on a normal day-night rhythm so it knows when to hunt; and it wants a view, because a spider that can see across a room is a spider that spends its day watching one.

Room temperature means yours. Somewhere between 20 and 27°C is comfortable, and the honest version of that is: if you are comfortable in the room in a t-shirt, so is the spider. Below about 18°C it slows down, stops hunting and eventually stops moulting. Above 30°C it burns through its reserves. Neither is an emergency for an afternoon, and both are a problem for a fortnight.

Water is the thing new keepers get wrong in both directions. A jumping spider drinks droplets, not standing water, so the routine is a light mist on one wall of the enclosure two or three times a week, aimed away from the spider and away from its hammock. It should be visibly dry a few hours later. A permanently damp enclosure grows mould and mites; a permanently dry one is one reason a spider goes off its food — though a spider that has stopped eating is more often about to moult, which the moulting guide covers.

Handling is optional and the spider is indifferent to it. Some will walk onto a hand and sit there, some jump straight off, and neither says anything about how settled the animal is. If you do, do it low over a surface — a fall from standing height onto a hard floor is one of the few things that genuinely injures them.

The single most common real problem is none of the above: it is a spider that has stopped eating, stopped moving and sealed itself into a thick hammock. That is not illness. That is a moult, and it wants to be left entirely alone.