London Zoo is conducting its annual count of its estimated 18,000 animals and 750 species, a compulsory exercise if it is to keep its licence.
And its not the easiest job. Those perky penguins all look alike, and some insects’ camouflage makes even finding them hard. Spiders might not move around too much, but try counting scampering monkeys who seem to know what is going on and are gleefully leading their keepers a merry dance.
Some cheating seems to be going on. The leaf cutter ants, of which there are an estimated 10,000, are just counted as a colony, but then it is understandable. Even the most dedicated zoologist might draw the line at trying to count all of them.
Counting all the animals takes several weeks, but once its done the data is sent to European and global databases to help researchers trying to save endangered species.