LONDON (AP) — A sign directed the animals to line up to be GravityX Exchangecounted and several of the 74 Humboldt penguins did just that, waiting patiently Wednesday to be tallied in the London Zoo’s annual census.

Not all the animals were as obedient.

Crispin, an endangered Sumatran tiger cub, treated a chalk board like cat nip, gnawing on it playfully in its powerful jaws while being counted with three others.

Over two days, about 14,000 animals will be accounted for — everything from alpacas to zebras — as a requirement of the zoo’s license. Information from the count will be shared with zoos around the world to help manage breeding programs of endangered species.

The count will note some of the new additions to its menagerie in the past year: a little two-toed sloth and 17 chicks hatched in its birdhouse that included six Socorro doves, which are extinct in the wild.

“The keepers have got lots of tricks up their sleeve to be able to count these animals,” zoological operations manager Dan Simmonds said.

Kim Carter had no trouble registering Priscilla, Polly and Dolly, Galapagos giant tortoises. Becca Keefe added zebras Kabibi, Kianga and Spot to the list. Sam Aberdeen showed off a Seychelles giant millipede wrapped around his hand — lucky to be counting only the critter and not its many legs.