A hen house door?

Yes, and - any suggestions?

I have thought about this but have always worried about door failing or a
hen being shut out overnight.

This time of year our hens could go into the house any time between 7pm and
9pm. I was thinking of some sort of perch sensor to detect hens being
inside... but this got to complicated.

Another tack is to raise the hen house, see H-F Wittingstall (sp?) Riverside
Cottage books, or Bunny Guinness. These seem to work in France but it does
make cleaning and collecting eggs more difficult.

Colin