Q& A

BEHAVIOUR

Are animals ever afraid?

Fear is extremely useful – it helps organisms survive. Its roots can be found about 550 million years ago, when primitive worms evolved specialised nervous systems that helped them respond to external stimuli. Over time, animals evolved many different responses to fear. Some are instinctive – red-eyed tree frogs, for example, lay their eggs in trees but if a hungry snake approaches, well-developed eggs can quickly hatch, saving the tiny tadpoles, which then rain from the sky.

In other cases, the fear response must be learned. Australian conservationists taught endangered Tammar wallabies to be afraid of red foxes – a novel, non-native predator – by allowing them to watch other wallabies getting freaked out. Of course, non-humans