LONDON (AP) — Staff at London Zoo have begun their annual weigh-in of the facility’s animal occupants, from the tiny to the mighty.

Zookeepers will weigh and measure some 200 species including frogs, goats, penguins, gorillas and lions over several days starting Thursday. The results go into a database that is shared with zoos around the world.

Zoological manager Mark Habben said the weigh-in can help determine whether young animals are growing properly and have the right diet, and can even reveal whether animals are pregnant.

The zoo says its heaviest animal is an 852 kilogram (1,800 pound) giraffe, while the lightest are leaf cutter ants, weighing between 3 and 5 milligrams (a 10-thousandth of an ounce).