Giraffes aren't known for their vocalizations, a limitation thought to be caused by their long necks, but biologists have know determined that they do "hum" at night. According to cognitive biologist Angela Stöger at the University of Vienna, the animals produce a low frequency hum with "a complex acoustic structure." Hear it below!
"It could be passively produced – like snoring – or produced during a dream-like state – like humans talking or dogs barking in their sleep," Stöger told New Scientist.
Stöger adds that the hum could also be how giraffes communicate with each other when it's too dark to see.
