Given names often turned into family names when people were identified by their father's name. For example, the first name Ahrend developed into the family name Ahrends by adding a genitive s-ending, as in Ahrend's son. Examples: Ahrends, Burkhard, Wulff, Friedrich, Benz.
OK the definition you have used for crouching associates it with stooping (which on Wikipedia redirects to bowing. Squatting essentially involves bending at the knees and hips. If there is any bending at the waist (and maybe lowering of the head) then that is considered stooping.
Sleepwalking, formally known as somnambulism, is a behavior disorder that originates during deep sleep and results in walking or performing other complex behaviors while asleep. It is much more common in children than adults and is more likely to occur if a person is sleep deprived.