How do you treat a mayfly bite?

You can apply hydrocortisone or calamine lotion directly to the bites to help them heal and reduce itching. Oatmeal baths and aloe vera can also soothe itching. For persistent sores or ulcers, you should see a doctor.

Are mayflies harmful to humans?

The aquatic stage can't hurt humans either. Mayflies look similar to dragonflies, except their hind wings are smaller than the front wings, and they have two or three "tails," called styli. They are usually seen near water. ... They will not harm humans or any other living creature.