Hi all, my 2 gilts have been really scatching the last day or so. When i gave margaret (10months) a belly rub i noticed half a dozen mini crab like buggers on her belly and under her armpit. 1 was moving through the hair and when i touched it it dug in! They are on fresh ground that had sheep on it last week, and i also picked up some straw from a new place. What are they please, and are they a regular pest, or could they be recent invaders? help