Originally Posted by MichaelE
Fire ants are not found as far north as Detroit. Were they positively identified as such?
If so I would be contacting my local agricultural extension or etymology department at a local university.
Yes they were identified...I grew up down south and I've seen/stepped in my fair share of fire ant nests. What we believe has happened is the previous owner had imported a large amount of mulch to put down in parts of the lawn. You would not believe some of the weird things that have grown/came out of that bed. I don't know if you have ever heard of stinkhorns, but they basically a smelly fungus that is not native and the spores are carried in mulch that is imported from South America. 2 other people on my street have also found colonies in our neighborhood
EDITED: MichaelE, I am going to take your advice and just have someone that is an exterminator check it out...they look a lot like it and they were some visible mounds I saw once you pushed back some of the mulch. But agreed, couldn't hurt to make sure!