Do March Flies bite? This is the perennial argument at our place. They certainly feel like they give a good nip but I am informed that they do not have biting mouth parts so they can’t bite.
They do have a straight stout proboscis. The females use their proboscis to wound their hosts then mop up the blood. Unlike mosquitoes they don’t suck blood. As for being called March flies they seem to be appearing earlier each year and well before March.