So what's the story with squirrels?Do they lounge around all year in a nest, or do they only use a nest during nesting/breading times?
They are resident all year round, on and off, more likely to find it occupied when it rains. Supposedly squirrels have their young this time of year, so we're ever hopefull... Haven't had any activity over the last 5 days or so, I suspect they've gone away for half term... Over the last few months, we've had only one living in it, but last year we had up to 4 in there at one time.
Do you recommend auto or manual focus for a birdcam?
It sort of depends on what sort of camers a you're using. The raspberry Pi camera is fixed focus, which can be adjusted manually. For nestting birds you need to be able to predice the eight of the nest wneh setting you box up. You cant easily adjust it once in situ. Many webcams ahev an auto focus which makes this easier, but these cameras are often more expensive, and dont give as good an image. See http://nestboxtech.blogspot.co.uk/2016/01/why-webcam-autofocus-in-birdboxes-is.html