Do animals rely on darkness to tell them the time, or do they have an internal clock?
I have this raccoon that is messing with me by coming into my garage and trying to get into the dog food bin at night. I’ve combatted his efforts by closing the back door to the garage around 9 or 10 PM, and so far that has worked (Aside: I have to keep the door open during the day because that’s the only way the dog can get to the backyard).
But now I’m wondering if he waits until after 9 or so to come by to check the door, or if he just waits until a few hours after dark to come.
If he’s just relying on the darkness to make his move, I’ll have to start closing the door earlier, like around 6 (which kind of sucks because then I have to open 3 doors to let the dog out). If he is just going to keep coming around the same time every day, I can keep my current routine.
I guess what I’m asking is what does “noctournal” mean - “comes out in the darkness” or “comes out on third shift”?
My guess is that animals such a raccoon have “their rounds”. This starts under cover of darkness. If a pattern is working for them they will continue it. If an open garage door means food then that will be the first place to go after dark. If the door is regularly closed at the time of arrival, then they will return to it at a later time. If it is still closed then they will eventually change their routine and snoop somewhere else.
If there is food around, a raccoon will find it. Closing the door when it is still light out is a good way to keep the coon out.
Some researchers say that housecats have some kind of internal clock that is wonderfully accurate, on the timescale of a minute a day. This would facilitate their complicated system of territories, which are not fixed but rather move around on a daily cycle.