Chester Zoo is in the middle of a baby boom.
Over the last few months, animals such as black rhinos, giant anteaters and Asian elephants - which are endangered in the wild - have been giving birth to babies at the zoo.
Many of these species are extremely difficult to breed in captivity, so it's a real achievement.
The boom means the number of animals there is up by more than a third in the last year.
Nel's been finding out the secret of the zoo's success.