BBC: The larva of Calindoea trifascialis, a species of moth native to Vietnam, wraps itself in a leaf, drops to the ground, and then spends three days hopping around blindly until it finds a suitable spot to pupate. Although it cannot see through its leafy cover, the insect instinctively avoids sunlight by jumping along until it finds a shady spot. To see exactly how the insects move, Kim Humphreys of the Royal Ontario Museum in Canada and colleagues designed transparent leaf rolls from plastic. According to their study published in Biology Letters, the caterpillars were observed to anchor their rear end to the floor of their shelter and lower their head, then jerk their front end backward, causing them to leap up and back. The researchers think the caterpillars drop to the ground to avoid predators, but then are vulnerable to overheating by the Sun and must seek shade. “Perhaps there are interesting aspects of the biology of other larvae that are remaining to be discovered,” said Humphreys.
The finding that the Saturnian moon may host layers of icy slush instead of a global ocean could change how planetary scientists think about other icy moons as well.
Modeling the shapes of tree branches, neurons, and blood vessels is a thorny problem, but researchers have just discovered that much of the math has already been done.
January 29, 2026 12:52 PM
Get PT in your inbox
PT The Week in Physics
A collection of PT's content from the previous week delivered every Monday.
One email per week
PT New Issue Alert
Be notified about the new issue with links to highlights and the full TOC.
One email per month
PT Webinars & White Papers
The latest webinars, white papers and other informational resources.