Kleitman often used himself as a subject in his sleep research, particularly on sleeplessness—whether in a pitch-black cave in Kentucky, in an underwater submarine during World War II, or on a trek ...

Researchers suggest that prehistoric cave dwellers created a model of the surrounding landscape, which might have been used for planning hunts. In the Ségognole 3 cave, located in the École ...

This is cave-dweller behavior, plain and simple. No class, no decency, just pure spite.” Added @QondiNtini, “We will stop talking about race when people stop doing things like this Deal?” ...