Since we just moved our chickens to our second home in the country, we would like to install an automatic door on our coop, as we are absent from the property during the week. We have an auto feeder and waterer, and an automatic door seems like an essential thing for our birds. Since we're gone a lot, what can be done to guard against a power or mechanical failure? I imagine having two doors for redundancy would be a good idea, but doing so, doubles the cost. What say you all?