From the DMF website:

A night crawler has about 150 segments! They have 5 hearts, 3 principal blood vessels, a nervous system and are 80% water.
They have no eyes and no sense of smell yet are sensitive to taste, light and even vibrations.
Heads or Tails?
* Pointy end is the head.
* Flat end is the tail
Night Crawlers are Strong!…..
A crawler weighing 1/13 of an ounce can move a 2 oz. stone…
(that's 60 times its own weight)
Dying worms turn into gas that can kill nearby healthy worms. The healthy worms will push sick or dying worms to the top of the dirt
Crawlers grow 1 inch per year. Average fishing worm is 6 or 7 years old
They can live to be 20 years old ! (If they don’t end up on a hook!)
Night crawlers are hermaphrodites. Breeding is highest in the spring and immediately before winter sets in
Worms are known to burrow 8 to 12 feet
They lay eggs in their burrows.
A mature breeder (2 yrs. old) breeds every 2 weeks producing an egg capsule every 7 to 10 days. Each capsule can contain 2 to 20 young and hatch in 14 to 21 days.
It is possible for a mature breeder to produce 1200 offspring a year.
It is estimated that 200 mature breeders can produce 1,000,000 offspring in a year, which in turn can produce 1,000,000,000 earthworms in 3 years!