Hi Erin,

One of our entomologists confirmed that they are not insects.

My first instinct is that they are very small, immature slugs. It looks like they just hatched. 

We got a lot of rain when you were away for two weeks. I am guessing that slugs that might have appeared over months in a normal year all hatched at once.

Are they slimy? Do they move? 

Lindsey K. Kerr, MS, MHP (she, her, hers)
Consumer Horticulture Educator
Michigan State University Extension

Hi Erin,

I admit, you have me stumped. 

Can I ask where you are in Wayne County? You don't have to be too specific--either a town name or general area (southeast, northeast). 

I'm wondering if you have spongy moth caterpillars eating trees in your neighborhood (they used to be called gypsy moths)? Maybe you have something eating your trees and their feces are falling down into your yard? A couple years ago, the cemetery in Huron Charter Township had an infestation of spongy moth. I could hear the frass falling down from the trees when I walked there. It sounded like rain!

Have you seen any signs of caterpillars in trees in your area?

Hi Erin,

I will ask my team if they have any ideas. I'm stumped! 

I will get back to you as soon as I can. 

Hi Erin,

One of our experienced volunteers thinks you might have what is called artillery fungi. I think she might be right! An article says "artillery fungi are often referred to as “ballistic fungi” since they expel their spores either by water splashes or by their own energy." 

Please read and look at the images in this publication and see if it doesn't look like what you have at home.

Lindsey 

I don't think this fungus is anything to really worry about. It's messy, but I doubt it will hurt your plants. We had such dry weather and then, while you were gone, we started getting rain and everything from fungus to weeds to bugs and bacteria, went crazy. 

I had never heard of artillery fungus either! I learned something as well. 

Thank you!