Chiggers is the name given in North America to a skin parasite called Trombicula autumnalis.
In Britain we tend to call it the Harvest Mite due to it's presence during the summer and autumn. Only the larval forms are parasitic and with extremely good eyesight may be seen as a small orange dot on your pet's skin surface. They climb onto your pet off the foliage, tending to congregate around the head and neck in the cat and the feet, limbs, armpits and groin in the dog. Once 'on-board' they take a blood meal before falling back onto the foliage. They can be very irritant, so if you see your pet chewing or scratching these particular areas, with a rash and scabbing developing from June to October, this may well be the cause of the problem.