How do animals know how to scare off predators?

Animal expert Eleanor Drinkwater explained...

Eleanor - It's a deep area of controversy at the moment in the animal behavior community. The idea is that a prey animal intentionally startles its predator. It could be that it lets out a noise that causes a fright, or it could be a colour display, or it could be a smell, or it could even be bioluminescence. There's a range of different things. The really difficult thing is how is this working? For example, there's the hypothesis with some of the lovely moths you see with the big eyespots that's they are trying to frighten their predator by thinking that there's another predator there. And so it could be that kind of almost mimicry, which is causing this kind of surprise. Or it could be that it's just the kind of blinding flash of kind of colour and noise which triggers fright, but ultimately it's something which is very difficult to measure. But interestingly, this is often tied in with the knowledge of the predators. And so this is something else which is currently under investigation, and it could be the case that some of these kind of startle defenses work really well on naive or kind of young individuals, but then wear off as the kind of predator becomes wise to it. So it's a really interesting area of research. That's a really, really good question.