Is my rabbit nesting?

Question
I adopted my rabbit a couple of weeks ago from a shelter. We didnt get her fixed because they didnt know wether or not she was pregnant so we were going to wait a month and see what happend. We use a cat litter box with a top on it, she is litter trained very well, never even poops on the floor. We also have an open cage in her pen. She always used her litter box till a couple days ago and when I went to clean it, as I do everyday, it wasnt dirty at all, just some hay and carefresh. I also noticed that she had started pooping and peeing in her cage. Then it seemed like she was going through her hay like crazy. But then I noticed something, her mouth plum full of hay. She looked like she had a mustache lol. She was taking the hay to the litter box. She has also been digging in there like a crazy bunny, all day it seems like. So, does this sound like shes building a nest inside that litter box where she is taking all that hay and digging all day? By the way, she isnt sleeping in there or laying on the hay, she still does that inside or cage or outside in the pen. Sorry this was so long I just felt like I needed to give you all the details. Thanks

Answer
Hi Tabitha,

usually they pull off fur and line whatever 'nest' they are building.  It could be the case she is pregnant, but they usually don't make a nest in a place they use for a bathroom.  Since she was trained to use litterpans as bathrooms, it may not mean she is pregnant.  If you don't know how old she is, she may be hitting sexual maturity, which would explain the marking of territory.

Some of her behavior (digging, etc) can be explained more by the time of year.   They tend to dig more in the spring, whether they are fixed or not.

Lee