Banham Zoo caries out its annual census
3 January 2014 Last updated at 11:52 GMT
Life for the keepers at a Norfolk zoo would be a lot easier if the animals did come two by two as they carry out the annual census.
Every specimen, including about 1,000 cockroaches, has to be counted.
The numbers are then recorded in a global database so that other zoos with the same species can share information and so help breeding programmes.
Mike Liggins reports.