Could someone please tell me a bit more information about the chiggers?

They are mites.: Very very tiny arachnids, relatives of spiders & ticks. They live & feed on vegetation like grain, grasses, & briar bushes. The immature larva drops onto humans (or other hosts) & injects a very irritating substance into the skin in order to feed. Then they drop off after a few days leaving a cluster of intensely itchy skin lesions. Treatment is antihistamines, cool compresses, & topical steroids.

Dr Galbrath gave : Lots of good info. Chigger's bites often have a small red in the center of a welt & occur in areas where skin is tender like the crotch, armpits, beltline, backs of knees, ankles. They are extremely itchy. Chigger bites usually heal on their own within one to two weeks. In the meantime, control itching with an over-the-counter anti-itch cream, such as Hydrocortisone cream. Consult your doctor if.