It's common for pullets to lay where ever. . Takes them time to firgure out boxes... I use a dummy egg in boxes.. that usally helps... make sure nest boxes are clean
Of course there happy. There on a heat mat... generally not a good idea.. since its only 7 degrees it will be on all the time...they'll be cold once they step off it.. so won't want to leave it... Chickens can handle cold... windbreaker is good.. heat pads or lamps bad..
I run 45% first 18 days.. 70 last 3..
I use a small pill bottle next to egg turner by motor..
That's usally all I use first 18 days..
Ya need a guage to monitor it.. I'd get one.. not to late since your only at day 4..
I'd wait to candle..
38% humidity in the room..doest mean it's 38 in...
Have you seen the stc1000.. temp controller?
Look it up.. it will likely be alot better then a home thermostat and the water heater one.. and it's cheaper