I have these strange ant hills all over one section of my lawn. They’re just single holes with a ring of dirt around them. Not the hills you usually see. What can I do about them?

First of all, those aren’t ant hills. What you’ve got there is a swarm of night crawlers that have nested in your lawn in the fall and hibernated over winter. Night crawlers are thick long worms often used as lures when fishing. Night crawlers don’t usually cause any serious or permanent damage, although they can sometimes leave your lawn very bumpy, like you’ve got golf balls under it. In that case, the best remedy is to aerate to reduce the compaction in the soil. In extremely serious or dry conditions, a second aeration may sometimes be required in the fall.  Top dressing the lawn will also help to fill in the gaps between the bumps.