Dolphins

Noise from ships and boats are causing dolphins to make their calls less complex, according to a new study.
Honey the dolphin, along with dozens of penguins, were left at Japan's Inubosaki Marine Park Aquarium when the place closed.
But what they did discover was still really amazing.
There's a big reward for anyone who helps find the killer.
They'll be deployed in Mexico this spring to help locate the world's rarest marine mammal.
Does this mean they have their own human-like language?