Hair grows everywhere on the external body except for mucus membranes and glabrous skin.
Such as that found on the palms of the hands, soles of the feet, and lips.
Hair follows a specific growth cycle with three distinct and concurrent phases: anagen, catagen, and telogen phases.
Each has specific characteristics that determine the length of the hair.
All three occur simultaneously; one strand of hair may be in the anagen phase, while another is in the telogen phase. (source)
Can guinea pigs eat human hair?
No, they cant eat human hair at all. It is too much for them to try and eat and they will choke on it.
For more things that guinea pigs can and can’t eat check out our guinea pig food list.