I was weeding/newspapering/wood chipping an area this past weekend where I will grow cucumbers up a trellis. As I pulled weeds, many worms were coming up out of their holes. So I wouldn't injure them, I would toss them back into the area that I'd already weeded.
This reminded me of the times I've heard that if you cut an earthworm in half it will grow back as two separate worms. I wish this was true but it's only a myth.
An earthworm may be able to regenerate itself if it is cut beyond its clitellum (saddle-like band around its body that produces mucus),with at least 10 segments (rings) still intact past that. The new tail that grows back may be smaller and paler than the original tail. The severed tail section will die. It cannot grow a new head. Worms can sever their own tails in order to escape being eaten by a predator. Best to let the bird have a little piece than all.
There is a type of flat worm, called a planarian (found mainly in ponds and lakes), that can regenerate itself from even the smallest of pieces. I find this fascinating!
Also fascinating, a worms ability to digest decaying matter and produce nutrient rich castings that can be used as plant food. The red wiggler is best at composting. They are smaller than the nightcrawler but have a heartier appetite. They live in the top 6 or so inches of the soil where it's warmer. They can tolerate the shallow soil of a compost bin and stand the heat of active compost and manure piles.
Nightcrawlers, on the other hand, do make castings too, just not at the rate of the red wigglers. They are most beneficial as soil aerators. They burrow down deep into the soil, where it is cool and moist. As they tunnel, they are constantly mixing the soil layers, taking humus down into the deeper layers. They cannot stand the heat like the red wigglers and their skin must stay moist. If held in captivity, they must be refrigerated and kept moist. They mainly eat the soil for the fungi, bacteria and protozoa it contains.
What great critters to have working with us in our compost bins and gardens. Be kind to these little helpers and try not to chop anyone in half.
With forty shades of green, it's hard to be blue.
Garg 'nuair dhùisgear! Virtutis Gloria Merces
One of the things I have long wondered about worms, is why they seem to come out of the ground and die after a rain.
I understand getting out of the water-logged soil where they can't breathe, but why, after escaping to the top, do most of them then seem to expire?