Have finished making the electric hen :)
Cut the wood up, screwed it together and put i few coats of varnish on so I can wipe it down when it gets covered in chick poo! Stuck the heat mat on with gaffer tape. Screwed in the hook eyes.
The top, which will be suspended at an angle by chains and hung in the brooder:
The heat mat which the chicks sit underneath:
They use a lot less energy compared to a heat lamp, so less cost, and they're more natural so the chicks can get used to daylight hours etc.
Apparently chicks feather up faster under them, but don't know as yet :)