She's come in today with a tic (i think) on the front of her head just in front of her ear. It's not filled up (ie a big disgusting white lump) it's a little brown/black disgusting thing with legs. I tried to get it off with a flea comb but it's stuck in. I know you are meant to put something on it to make it pull it's head out but i cant remember what......any ideas?