This is what we have been working on this morning. We seem to have with mice coming through the vents so we came up with a solution. I purchased aluminum window screen (so they can’t chew it) and shaped it into a box so that it fit into the vent, then used metal tape to secure it. It also will help with things getting lost down the vent. Not that anyone else has problems with anything going down into vents do they Tressa.