I came across this stuck to my fence. I looked at it from every angle, but I still can’t figure out what it is. Does anyone know what it is? Check the first comment for the answer

 

That object stuck to the fence mesh is an expanded piece of expanding polyurethane foam sealant (commonly sold under brand names like Great Stuff).

How It Ends Up on a Fence

• Squeezed Through the Mesh: When expanding foam is sprayed—often during nearby construction, fence installation, or repair work—it comes out as a sticky liquid viscous gel. As it reacts with moisture in the air, it expands dramatically and pushes through small openings, such as the diamond gaps in metal mesh.
  
  
• Cured Shape: As the excess foam expands freely on the other side of the fence, gravity causes it to sag and curl into irregular, bulbous, or organic-looking shapes before it fully hardens.
  
  
• Weathering: Over time, exposure to UV light turns the outer layer of polyurethane foam a beige, tan, or yellowish-brown color with a dull, textured, or skin-like surface, making it look surprisingly like a bizarre fungus, gall, or cocoon.
  
  

How to Remove It

1. Mechanical Removal: Once cured, expanding foam is no longer sticky. You can easily break or slice it off using a utility knife, putty knife, or hands (wearing gloves).
   
   
2. Scraping Residuals: Any small bits remaining stuck in the mesh can be scraped off with a wire brush.
   
   
3. Solvents (Optional): Acetone or nail polish remover helps dissolve uncured foam, though fully cured foam usually requires mechanical scraping or dedicated foam cleaners.