Proc. Natl Acad. Sci. USA doi:10.1073/pnas.0806830105 (2008)

Like many spiders, Erigone atra, which tends to live among crops, has a choice to make when it decides to move. It can either spin a silk sail to 'balloon' a relatively long way, or spin a rope and rappel a shorter distance.

A team led by Dries Bonte of Ghent University in Belgium has discovered that the temperature that E. atra experiences during development influences the means of transport it chooses. The researchers raised 520 spiders in Petri dishes and then placed them on platforms in a wind tunnel. Spiders raised under cool, spring-like conditions tended to balloon, whereas those raised in summer-like conditions preferred to rappel.