Another moveable chicken house

I like the idea of easily moveable chicken houses with integral runs. The chickens can be moved around the garden to fresh grass. If rats move in (as sometimes happens) everything can be picked up and moved and the rat holes safely baited with poison without posing a risk to the birds. But due to the inevitable size restrictions I do feel that chickens kept in this type of housing should be allowed time out of their pen to free range the garden.