Wondering if anyone has seen this type of pest damage?


none of the wood was touched.

just the Polystyrene Foam board

wasnt sure, if those were mouse droppings or not…

any ideas!

I am guessing ants. I would like for @mgoldenberg to chime in.


Looks like some type of beetles that got lost & failed.



thanks for the replies !

Carpenter ants. Notice the ant body parts in the frass; they keep their living spaces free of their dead. Also carpenter ants don’t eat wood, so they can live in various materials (like treated wood, or even foam, apparently). Those channels are the living spaces.

Was there a clear covering on that foam? What if anything was removed to take the picture? What’s your location? What floor is this on?

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