Yes, and Yes. My newts (t. grans and cynops orientalis) both eat nightcrawlers.
You need to chop of the really dark end (the head) because it can irritate the newt after eaten, so don't feed that part (I don't know, but to be safe I don't feed the tip of the tail either)
And then they have to be chopped into small enough pieces to eat. My newts will spit it back out and then refuse to eat if I haven't cut it up small enough. I suppose it's just because those worms are so thick, they have a hard time getting it down if it isn't cut small enough.