Birds nest--cowl plugs not enough

Who knew an RV-4 could carry 4 passengers? My brother (taking care of my plane while I'm overseas) flew my plane to get the conditional done. Upon taking the cowling off discovered the following bird's nest complete with 4 eggs. He uses cowl plugs so the only way the bird could have gotten in would be through the exhaust area. I know the question has been asked before about plugs for the exhaust area but have not seen an answer if anyone uses anything down there. I know birds can build a nest within hours--this was less than 2 weeks. Has anyone else had bird's nest problems while using cowl plugs?

Did they turn out soft or hard "boiled"?

how big a hole???/

it's been noted that some swallows and finches can get thru a hole that seems only nickel sized!!!
since the question was asked........
I started putting screens rough cut to the gaps around the exhaust pipes & cowl exit area, when we had a marmot problem on the field. hot pipes not a problem, as they cool off so quickly.
big inlet plugs, and closing the snorkel 'flap' ( carb heat - HOT) seems to do a pretty good job of keeping out the critters.

This is not a criticism; just a comment.......when I preflight, if I see a single shard of grass or other foreign object, that's a reason to delay the flight, and uncowl as needed. gotta assume there is more.
Looking thru the small oil door with a good flashlite should catch MOST of this, but no doubt there are areas on the far side of the engine that simply can't be viewed without a mirror. ( another reason to have TWO access doors, one on each side!)

glad it turned out ok! thanks for sharing.

I am jealous of how easily bonanza pilots can check their engine with those hinged cowl
panels. wish the RV's had that option, especially for pre flight inspection.