Chimps love to groom and to be groomed. They can be particular about where they want to get scratched though, using 'referential gesturing' to draw the attention of another chimp to the specific area they would like to have groomed.
7. Geckos “Seamless” Their Food
Day geckos are native to Madagascar. They communicate by simply nodding their heads at treehoppers - insects that digest sap and excrete it in honeydew. When the gecko communicates to the treehoppers that it would like some of the honeydew, the insects oblige, excreting it right into the amphibian's mouth.
8. African Demon Mole Rats Head-Bang
These critters communicate through head-banging. They spend their lives underground and can communicate with one another by thumping their heads against the tops of their tunnels. This way, they send vibrations through the earth that travel much further. In addition, the pace and intensity of thumps indicate different meanings.
9. Dholes Whistle
Also known as Asiatic wild dogs, dholes are also sometimes called whistling dogs - and with good reason. These fox-like animals alert each other about the location of prey through whistle sounds. This enables them to make coordinated attacks on other animals, including animals that are much larger than them. They communicate in packs to take down prey that is more than 10 times their own body weight.
10. Black-Footed Titis Squeak
In case you're wondering, a black-footed titi is a brown, rainforest-dwelling monkey. They use high-pitched squeaks to let each other know not only what types of predators may be near, but their location. Researchers have found that the monkeys vary their calls in a variety of ways, including creating their own syntax and complex communication system.