What did you do with the not drowned mice?
I've tried letting them go alive in the run, they got out.
Put them in the HC lined coop and one old girl knew what to do....the rest learned from there.
Even tossing in dead ones it' takes them awhile to figure it out and them a longer while to get...
I've been thinking about building one of these. Problem is water would freeze here now and didn't want to use antifreeze because of overall toxicity...but windshield washer fluid would work, not sure about toxcity with that. Plan on just disposing of the corpses in the garbage, but I have dogs...