Fascinating Facts About Spider Webs

Ranging from northern Europe to Siberia, the water spider, or diving bell spider, is the only spider species that lives entirely in water (per Animal Diversity Web). It owes this aquatic existence to its silk.

To establish itself, the spider casts webs between plants underwater. Then, it swims to the surface, exposing its abdomen to the air, where the spider’s hair snags little bubbles of air. The spider swims back to its underwater web, where it plants the airdrops. This results in an underwater cave held in place by a webbed ceiling. Then, bit by bit, the spider expands the structure to make a more capacious den.

Diving bell spiders use these nests as their base camps and hunting blinds. Threads of silk from the nest protrude into the water, where if a prey item hits it, it signals the spider to pounce. The nest is also where the spiders can molt, mate, or just enjoy a leisurely meal. Most importantly, the den acts as a cache of breathable air. The spiders can detect if oxygen levels are getting too low. When that happens, the spider swims up to collect more air. During the winter, it swims deeper and builds stronger nests in objects such as snail shells.