I have a small coop and the regular heat lamp would not fit so i tried the small 75 watt reptilian heat lamp and my birds would not go in the nesting box at night if the red heat lamp (only 75 watt) was on so in 20 below zero weather i had to shut the light off and pray each morning my birds were still alive. I have 20 bales of hay surrounding my coop and run to insulate some, then I have 2 moving blankets on top of the coop itself with tarp on top of that. Then the consistent 20 below zero came back and i read about a farmer using seedling heat mats in his egg box so I thought I would try it in one box. I put the heat pad inside a flat veg can box. I then placed another flat box ontop of the heatpad topped off with hay and the heat pad is folded up in the back of the nestbox along with the wire. I attached the wire to my outdoor extension cord connected to a thermostat controlled plug (on at 35 off at 45) so now i wait to see how warm the box gets and if it will be safe. Will be going out to check each hour today to see how warm it gets. if anyone has any experience with using seedling heat mat please give me some tricks. My birds have dropped from laying 3 eggs a day to 2 eggs to 1 egg every 3 days and it is so freking cold here!! I almost want to bring my 3 RIR inside (ha ha) My RIR are 11 months. You see golf balls in each nesting box. I use them to try to get my hens to lay in both boxes but they push the right side ball over to the left box each day - for some reason they will not lay in the right nesting box. They are both clean no draft so i am puzzled.