Keepers take stock at London Zoo
They can dive, swim and glide, but even the penguins at London Zoo will find it difficult to hide from keepers who have the tricky but essential task of counting every animal in their care.
Some of the world's most endangered species, including rare penguin breeds and two new lion cubs, will be counted for the first time in this year's stocktake.
Macaroni, blackfooted and rockhopper penguins will be among those totted up in their new 1,200 square metre home - the largest penguin pool in the country - along with 752 different species at the zoo.
Adrian Walls, team leader of birds at the zoo, said: "We built a very naturalistic environment for the penguins so they can come and go and swim around. We work with these birds every day so we know their characteristics and we get to know most of them individually."
The stocktake is required as part of London Zoo's licence.