Straw-coloured fruit bats in Kasanka National Park, Zambia

© Nick Garbutt/Minden Picture

And the skies filled with bats…. And the skies filled with bats…

Right on cue for Halloween, millions of straw-coloured fruit bats begin to descend on Zambia’s Kasanka National Park from the end of October through to mid-December. These large bats pack into a small area to roost but when the sun begins to set, they start to swarm, darkening the skies as they fly off to gorge on fruit in the Mushitu swamp forest. No wonder they are hungry - their migration is thought to begin 2,000 miles north, in the Democratic Republic of Congo.

There are more than 1,000 species of bats which fit neatly into two categories: microbats, which typically use echolocation to find what they are looking for, or megabats, which rely on smell and sharp vision. The straw-coloured fruit bat is of the mega-variety. They are the most widely distributed of all African fruit bats and also play a critical role as pollinators and dispersers of seeds. They live in large groups called colonies which can number from the thousands up to a million. But don't worry, they don’t drink blood.