In Batesian mimicry, the mimic is a "sheep in wolf's clothing": it looks like something dangerous or which tastes disgusting, but in reality it is good to eat. As he was exploring the Amazon valley in the 1850s, Bates collected butterflies. He saw how some harmless butterflies looked like other species which were toxic. Birds avoided them, so "the mimics survived even though they were good food". This was the first scientific account of mimicry.