why has she started to grunt

Hi i am asking for some help on behalf of a friend .
On thursday last week she went out to her rabbits cage she has 2 female lop ears together .1 of the rabbits was pulling fur and had made a nest they are both definatly female so we can only suppose it was a phantom pregnacy. She has now stopped this behavior but ever since has been grunting quite loudly even when in the cage and my friend is at the other end of the garden .Has anyone come across this before or have any ideas why she is doing it or how we can stop it. The rabbit is eatting and drinking as normal and doesnt seem to be in any pain

Are the rabbits neutered?

Probably her hormones. Is she grunting when your friend is going to the hutch? She is probably protecting her hutch. She needs to be neutered.

the rabbit is grunting if my friend is near her or not .she can hear it grunting from the back door the rabbit cant see the back door so its not as if the rabbit can see her approaching .
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Not sure if she is nuetured but i will mention it to my friend.
Thanks

It's unlikely she's neutered if she's having a false pregnancy.
Unneutered females can be very territorial and that's probably what the growling is about. She wants to protect her own nest area as she see it. There is a danger they will start fighting very badly. I would definitely advise your friend to get they both neutered as soon as possible, and to take them to the vets together when she does