When defensive, guppies display a warning sign to their counterparts. 

An online survey finds that people report feeling most relaxed with a glass of red wine or beer, and most aggressive when drinking spirits.

Hermit crabs living in broken shells outperform those inhabiting intact shells in fights because they attack more aggressively, compensating for lower muscle strength with vigor.

Automating Drosophila behavior screens gives researchers a break from tedious observation, and enables higher-throughput, more-quantitative experiments than ever before.

New research shows that using mirrors to elicit aggressive behavior from animals may not be a fool-proof plan.

Reef fish, once thought to be unable to see red wavelengths, not only fluoresce deep red, but males of some species react to seeing their own bioluminescent pattern.

In Chapter 3, “Tamping the Simian Urge,” author Travis Rayne Pickering contrasts the brute physicality of predatory chimpanzees with the headier hunting style employed by humans.

Meet some of the people featured in the April 2013 issue of The Scientist.

Archaeology can shine needed light on the evolution of our aggressive tendencies.