Humane Mousetrap Capture Beacon




We use the mouse traps that don't kill the mice. With only capturing a mouse every few weeks we forget to check the trap and have had a few die because we forgot to check them which completely defeats using the humane trap in the first place.

Now we get a bright LED light in the garage near the fridge that lets us know when a mouse has triggered the trap.

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Step 1: Instrumenting the Trap

Using a normally open reed switch and a small magnet you can make the reed switch close the circuit when the gate on the trap closes.

I used a small nail in a drill to make two holes in the trap to mount the reed switch

I used a soldering iron on low heat to melt a pocket to mount the small magnet

After fitting the reed switch over the door and the magnet in the door we added glue to hold both in place.

The trap now acts as a switch that is open when armed and will close the circuit when an unlucky (but more lucky than the last two) mouse enters the trap and the door closes.

Step 2: Building My Beacon

At the current time I only wanted a noticeable light when the trap triggered.

I had an old wall-wart phone charger which would supply a tiny 250mA of 5V that had been kicking around for years.. It fit this project perfectly.

Generally you want to run about 10mA through an average LED.. Since there is a 0.7V drop across the LED the resistor calculation is (5.0-0.7)/0.010 = 430 Ohms.

I had some bigger LEDs so I actually used slightly smaller resistors..

I mounted the circuit to a board I had laying around and screwed it to the wall in a normally dark but very visible location

Step 3: Attaching the Trap-Switch

I had some handy experimenter single conductor sockets that fit nicely over the leads of the reed switch.

Alligator clips or some sort of connector should be used because you want to be able to disconnect and take the trap to a distant location to release the mouse.

Step 4: Hopefully the Magnet Will Not Spook the Mouse...

I haven't bated it yet but here is the armed trap sans bait.

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6 Discussions


3 years ago

"House" rodents will seek out structures that are familiar to them. They are not equipped to live in the outdoors. They wil either move to someone's building or become owl food.


3 years ago

What do you do with the humanely captured mouse? Is there a preserve somewhere? Leaving vermin where they are not wanted is vandalism.

1 reply

Reply 3 years ago

We just release them at the end of the driveway.. 3/10 mile away. If he comes back and get's stuck again he'll get the free ride again.. I have no idea or interest in how to mark a mouse to locate repeat offenders.


3 years ago

I'm so happy you care enough about not killing mice to make a project about it!! Great idea. Keep sharing!

2 replies

Reply 3 years ago

It could be that I'm just tired of discovering dead mice that we had intended to set free.. Purely selfish!


Reply 3 years ago

Not selfish at all to be humane. The comment about leaving vermin where they don't belong was unfair. I believe you probably released it or them in a field or forested area not on your neighbour's front porch. You are a good person to take the extra time to do a kind act for some of God's little creatures that may be a nuisance in your residence, but part of the ecosystem in the wild.