What the heck is making these holes?

check · Oct 16, 2018

Hello guys, I have a real puzzle on my hands. The wodden floor of my old barn is growing holes!

Something is drilling perfectly round holes through the wooden floor members, each of which is about 2 inches thick. A couple of the holes are a bit bigger, but mostly they are about 1 inch across and cut as neatly and cleanly as if I had drilled them with a drill myself. I have seen carpenter bee holes, but they are much, much smaller.

Any ideas what critters are making these holes?

My barn is in a colder climate, about 2 1/2 hours north of Toronto.

mikester · Oct 16, 2018

Post a photo and some dimensions. I would have said carpenter bees at first but those are a nice round 3/8" diameter hole

oosik · Oct 16, 2018

I had one mouse hole in my storage shed - about 1" - but that was going thru 3/4" plywood flooring - not 2" flooring. Come to think of it - it was a bit ragged also. Covered it with a metal lid off a can of Copenhagen - glued & screwed down.

Adds that distinct flare to the Tuff Shed - my motorcycle storage shed.

Diggin It · Oct 16, 2018

Look at a mouse or rat hole close enough and you'll see the gnaw marks. Without those, I'd have no idea. Any way to set up a camera?

tvman · Oct 16, 2018

check said:
Hello guys, I have a real puzzle on my hands. The wodden floor of my old barn is growing holes!

Something is drilling perfectly round holes through the wooden floor members, each of which is about 2 inches thick. A couple of the holes are a bit bigger, but mostly they are about 1 inch across and cut as neatly and cleanly as if I had drilled them with a drill myself. I have seen carpenter bee holes, but they are much, much smaller.

Any ideas what critters are making these holes?

My barn is in a colder climate, about 2 1/2 hours north of Toronto.

Got the same thing here in Indiana. Our's was caused by bumble-bees. The big black and yellow type. They are persistent little buggers.

Diggin It · Oct 16, 2018

As the OP noted, bees make a hole about 3/8" or so, just big enough for them, not an inch or so in diameter like he's seeing. I've also never seen a bee hole in a floor, only in rafters and posts up higher.