A few days ago I opened the side cockpit door of my Cherokee 140 to find bird poop on the seats, floorboards and even some on the glare shield. At first I assumed something got through the hole for the nose gear and made it’s way through the hole for the rudder pedals but that hole is really small and didn’t seem that plausible but how else could he have gotten in? I would have noticed a bird flitting around when I buttoned it up the previous week so he didn’t get in the easy way. I posed the question on the AOPA group on Facebook and among some of the more smartass answers one very helpful member mentioned the air scoop under the aft seats that critters can crawl up and get into the cockpit if the holes in the front of the lid of the box underneath the aft seats are large enough a critter could get in. The user mentioned using chicken/rabbit wire tucked into the hole would solve the problem which I might eventually do but for now I’ll just keep a piece of foam stuffed into the hole and add removing it to my preflight checks.