Bees can taste the pollen they collect, and favour the sweet kind.

Felicity Muth and her colleagues at the University of Nevada in Reno offered bumblebees (Bombus impatiens) an artificial flower containing one of three types of pollen — sweet, bitter or unflavoured. Bees presented with the sweet flower spent longer collecting pollen than did those offered the other types. When the bees were presented with two more flowers, one of which was the same colour as the first, few bees opted to change colour if their first flower had been sweet or unflavoured.

Many plants rely on bees for widespread pollination, so plants may have evolved pollen just sweet enough to keep bees coming back for more, but not so sweet that one bee takes it all, the authors say.

Biol. Lett. 12, 20160356 (2016)