Found these today looking through an old barn this morning. Thought it was neat. My uncle worked for this particular one back in the 60’s

traps?

I believe they are mink boxes, although I’m not sure really how all that worked. I do know where we live has an extremely high per capita mink ranch population. Something to do with the soil content maybe? Not sure

cool

Awesome

Also found these, lots of different sizes

And they are yours just because you found them in someone else's old barn?

Those boxes could be nest boxes.
When I was a kid , a neighbor had a mink farm.
I and the neighbor boy were raising rabbits and bought his old cages that were about 4 foot by 2 x 3 foot , and a nest box on the back side.
Had to cut a larger hole in the back of the cage ( it was wooden) and in the nest box for the rabbits to get in.
Wound up building bigger nest boxes for the rabbits.
The nest boxes looked similar to those.