Cephalopods are masters of camouflage. Scientists want to decipher how the process works in the brain.

We asked 100 scientists about unsolved problems in their fields. They sent back provocations — on the origins of life, the possibilities for human progress and much more.

© Photo illustration by Jane Stockdale for The New York Times

Scientists analyzed hundreds of encounters between bears and canines. The results raise the suggestion that dogs may not always protect people in the wild.

Scientists observed a family of pygmy raccoons near a Cozumel beach club learning from one another how to craft balls from paper, an indication that the animals have a culture.

Dog behavior experts offered a variety of explanations for why Nash the golden retriever wagged his tail and carried a toy near a man who broke into his owner’s home.

Tribes and scientists are mounting an urgent trapping effort to keep European green crabs from devastating a corner of Puget Sound.

© Chona Kasinger for The New York Times