problem with wild rats maybe harming our pet rabbits

Question
We have two pet rabbits, and we breed them. Currently, the female has made a nest out of fur, but there is no baby bunnies in it. She started building half of this on friday, and finished the other half on Saturday. It is now Monday and we don't have any bunnies. We think maybe a rat could have snatched them. Are rats predators? We are thinking this because a week or so ago I saw a rat run from the cage and it had tunneled under the cage and come up through a hole by the hutch door where our rabbits (or maybe a rat) has nibbled through the wire so there is a hole there. Also last year one time we found a week old baby bunny outside the hutch and we had no idea how it got there. So could this have all been related to a rat? Please reply asap. Thanks alot :)

Answer
Rats are predators, yes.  They are omnivorous and will eat pretty much anything.  So baby bunnies would not be outside their abilities.  

Since rats are also rodents, chewing and tunnelling are things they also do very well.

This isn't exactly what you need, but, will give you some idea of the scope of what rats can do, at http://www.nps.gov/chis/naturalresources/page8.html

To get rid of rats, basically you are going to have to start bating traps, and keep doing it until they are no longer in your area.  You will either need to kill the rats you trap, or release them elsewhere.  They carry all sorts of parasites, so getting rid of them would be a good thing for your rabbits.

Otherwise, move the rabbits into the house, with a new cage, and make sure it isn't accessible to the outside.

Kim