Buddy power warms tent caterpillars

A new analysis of life in a tent full of caterpillars reveals more heat and more insulation than scientists had expected.

The dark, fuzzy caterpillars of the eggar moth, Eriogaster lanestris, spin silk tents where 200 or so siblings cluster between their three daily, mass forays for food. Caterpillars can bask in sunlight to soak up warmth, but most earlier studies suggested that once the sun goes down, tent caterpillars were out of luck, says Claudia Ruf of the University of Bayreuth in Germany.