Bird closures are used to close entry points under roofing into your ceiling.
Starlings are one of the main culprits in this case, as they like to breed inside ceilings, causing lice infestation.
Bird closure is a flexible plastic comb-like bird proofing product. The "teeth" firmly nestles into the openings, preventing the birds from entering.
This is an effective and low visibility bird proofing strategy.