How do “goose pimples” form?

This is another term for goose-flesh, because cold or fear causes the skin to look like that of a plucked goose. What happens is that when we are cold or receive a fright or shock, nerves which control the tiny muscles at the roots of the hair are disturbed.

As a result, these muscles cause the hair to stand on end and produce the effect we call “goose-pimples”. It is a very faint trace of a reaction seen best in cats when their fur stands on end if they are angry or scared.