Sure , they would climb the wood, jump on the plastic and swing in.
At work we watched a mouse jumping from the microwave up against a cabinet door until it popped open. Answering the question of who was leaving the door open so the mice could eat the crackers.
It's not practical. It's people behind a desk in a fantasy.
I have a similar run. Also I am on a hill so my neighbors water runs through my poultry yard when there's a big rain or snow melt.
FB doesn't allow animal sales
People have to be creative and usually post in a private group so they don't get reported.
The "feed store " in summit takes roosters and resells.
https://www.facebook.com/share/1BuRS87xxY/
Also these FB groups might be a resource...