Although the Amazon has few large mammals, it has lots of different types. There are around 800 species, of which the largest group is bats. In fact, there are more species of bats in the Amazon than anywhere else. As with other animal groups, Amazon mammals comprise a fascinating fauna, including the world's biggest otter, a freshwater manatee and tree-dwelling anteaters. Many of these are rare and shy, hence not usually seen in the wild. Others, such as the pink dolphin, are difficult to photograph. Important groups of mammals include carnivores, monkeys, anteaters and sloths, tapirs, peccaries, rodents and bats.