Washington: Spiders are quite literally all around us. A recent entomological survey of North Carolina homes turned up spiders in 100 per cent of them, including 68 per cent of bathrooms and more than three-quarters of bedrooms.

There's a good chance at least one spider is staring at you right now, sizing you up from a darkened corner of the room, eight eyes glistening in the shadows.

Spiders mostly eat insects, although some of the larger species have been known to snack on lizards, birds and even small mammals.

Given spiders' abundance and the voraciousness of their appetites, two European biologists recently wondered: if you were to tally up all the food eaten by the world's entire spider population in a single year, how much would it be?