Fish: Archerfish prove they can count by spitting at computer screens

Previous research has suggested that fish have an innate sense of numbers, but critics say these experiments aren’t the final word. Now, a new study has shown that archerfish really can count

By Michael Le Page

Can fish count? An experiment involving archerfish spitting at computer monitors has provided the best evidence yet that they really can distinguish between different numbers.

Various studies over the past decade or so have suggested that fish have an innate sense of numbers like many birds and mammals do and are surprisingly good at mathematics. But these typically involved tests such as individual fish choosing to join the largest of two shoals.

Critics say these experiments show only that fish have a sense of …