Recently there was a discussion on our Facebook page about Nest Grunts. When the chimps are getting settled into their nests at night they will often make a hoohuhhoohuh sound which is called a nest grunt. Chimps in the wild will often make these vocalizations to check in with each other before bedtime. We’ve been trying to catch the vocalization on tape for the blog for some time now, and we were finally successful! It’s definitely one of my favorite times of the night.