Outdoor pet cage?

Some sort of live rat trap? My granddad had a moustrap where the mice had to go in, across a trigger that closed the door behind them, then climb up a tube, walk across a trap door that dropped them into a box and reset the door. hard to tell from the picture, but maybe this is a variation of that idea?

Smoker?

I think it's used for breeding meth rats

Looks like some kind of trap.

If it works, it isn't stupid.

I want there to be an inline fan in that ducting, I imagine thats why it's covered in rat blood

3€ Pfand waiting there when they're finished with the crates though..