This Ski Lift For Mice Is Actually a Practical Solution to a Real Problem

Jeff Renz lives on a pretty big rural property on a hillside, with a chicken coop at the top. It is all very picturesque. But there is a problem: field mice love the chicken coop. It is warm and has stuff to gnaw on. So, they gather in the coop and do damage, while their droppings create health risks. Renz lacks the heart for mouse carnage on a mass scale, so he built this delightful gondola system to ferry captured mice to the bottom of the hill.

The hill in question is quite steep, so trapping the mice and hauling them down to the bottom would be a lot of effort. This gondola automates the process, transporting the mice without any work on Renz's part. The gondola cars even double as traps. They have passive mechanisms to both catch and release the little rodents.

Most of Renz's labor went into constructing the gondola towers, which he cobbled together from wood. Those have rollers to keep the cable moving smoothly. A car’s windshield wiper motor pulls that cable through a chain running to a bicycle rim.

The basic design is similar to the human-sized gondolas and ski lifts you see at resorts, but there were challenges with constructing the cars and their hangers in a cost-effective way. The hangers have to grip the cable, but also need to travel through the bicycle drive wheel and over the rollers. Renz's 3D-printed the cars and the hangers, but had to put special care into the design of the hangers — though they ultimately just grip the cable with zip ties.

A hinged door on the top of each car drops the mice in and traps them. A hinged floor, mechanically triggered at the bottom gondola station, falls away to deposit the mice at the end of the ride.

The only electronic component for the entire project is a motor controller, which drives that windshield wiper motor. Each morning, Renz can check if any mice are trapped in the cars and if there are, he can activate the motor to send them to the bottom of the hill, then bring the cars back up.

There were some difficulties along the way, particularly with the PLA prints deforming in the heat. But the gondola system works surprisingly well and the mice don’t seem to mind the ride.

Of course, only time will tell if this actually reduces mouse activity in the chicken coop, or if that increases as the rodents learn to enjoy the free transportation service.