Mosquito fish don’t just count on each other for protection from predators — they literally count each other for such protection. These guppylike fish can use numerical information to identify the larger of two nearby groups of fellow fish, report psychologist Marco Dadda of the University of Padova in Italy and his colleagues in an upcoming Cognition.
Log in
Subscribers, enter your e-mail address for full access to the Science News archives and digital editions.