They'll change colors if you add different wine to them. I keep my separate so the flavor is separate.
The mother usually floats on top of the vinegar. It likes warm and dark. As soon as you move it to the light, it sinks into the vinegar and in a few weeks another layer forms at the surface.
You can see that I've had this vinegar going for a long time. That's a lot of mothers in there. Each of them can be taken out and used to start new vinegar. It doesn't take much mother to get a new batch going.
Some layers are really thin - I generally see thin layers in warm weather.
Some layers are really thick. I see these during cold weather.
These mothers can be cut into very small pieces and given away to folks who want to make their own vinegar [homemade is almost always best].
Interested in the details? Here's how the whole vinegar thing works.
I left the other mothers in a bucket to drain. They're full of good vinegar and I want to keep as much of that as possible.