This one has 2 segments in the antennae (smooth has 3) and no white line along the side where the body flares (that would be Rathke's). It has two tails (no tails are pillbugs).
If you don't know what woodlouse you have, but it has tails, use Crinocheta.
If you don't know which woodlouse you have, but it has tails, put it in Crinocheta.
This one has two segments on the end of the antennae, a light line at the base of the body where the edges flair out, and not a whole lot of bumps on top. If bumpier and no line: rough; if 3 segments in antennae: smooth.
Can't roll in a ball, has two tails. The last angle of the antenna has 3 parts (not 2). generally light colored on the flared part of back and then with a row of dark spots.
If you don't know which woodlouse you have but it has tails, use Crinocheta.
The only ones in NJ that can roll into a ball. They also don't have a pair of "tails" like woodlice do. There are two species here. They are difficult to separate. See here.
It's from Europe. Small and narrow, shiny, with a very black head and lighter but highly patterned back
