One of the world’s smallest primates, the Philippine tarsier, can talk to each other using ultrasound. This means that they are the only ones who can hear it! They can hunt for their food and warn one another about predators – using their very high pitched noises!

Tarsius syrichta are tiny – they are no bigger than a man’s hand.

Tarsius syrichta are one of only a handful of mammals that can send and receive vocal signals in the ultrasound range, including some whales, domestic cats and a few of the many species of bats.

And few of these can squeal, screech or squawk at the same sonic altitudes as the saucer-eyed tarsier, which up to now had been mistakenly described as being ”ordinarily silent,” researchers found.

Lacking the typical ”night vision” of other nocturnal creatures, tarsiers also have – in relation to their body size – the largest eyes of any primate on earth.