Interesting question from Mike:
I was wondering, do the worms sleep? It really seems durning
the day and early hours when I get up I can open the bin and see now
worms unless I dig around. At night (after 9 or 10pm) If I open the
lid to show company the worms, they will be up on the edges of the tub
and on top and moving around and very active. I read it is normal for
them to climb the tub and go back down. But I was just wondering why
do they only seem to do this at night? How do they even know the
different between night and day? These worms are just getting more and
more interesting everyday.
That’s a good question Mike, and unfortunately not one I feel confident enough to give you an authoritative answer for. I suspect that worms have periods of decreased activity like most organisms, but I’m pretty sure they don’t ‘sleep’ the way we do. Their nervous system, while probably pretty extensive for an invertebrate, is actually quite basic by our standards.
I think I can shed some light (no pun intended) on the fact that your worms are more active at night though. Most (if not all) earthworms are highly sensitive to light due to an array of photo receptor organs found in their skin. You’ll notice that if you shine light on your worms they will move down into the bedding fairly quickly. Natural light is especially strong, so even if your house lights are on in the evening, it’s probably darker in your bin than it would be during the day (assuming your house lets in a fair amount of natural light).
Worms are also sensitive to vibration (easily created by all range of human activities), so they are also more likely to venture out from hiding when there is less activity outside the bin in the evening and at night.
Just my 2 cents worth, Mike!