When researchers discovered that cuttlefish have the ability to make themselves suddenly appear larger, they presumed that this behavior, called a startle display,  was used to scare off predators
A long-term study, however, reveals that cuttlefish never use startle displays to scare off predators but instead only use such displays to scare off small fish that do not prey on cuttlefish
Groups of small fish are likely to attract a cuttlefish's predators .