It looks like it came from some form of pest, but there are no obvious holes or material above it. It’s between glass and a screen with no obvious openings or holes. None of my other windows have it. We did have the house re-insulated recently, but I don’t think it looked like this. Any help identifying what’s going on?
I’m geographically located in Northern NJ I’m the US in the suburbs.
I have has that with fireants and the foam in alot of windows and doors. Is it foam bits perhaps?
It does look like foam to me.