spaying her might 'fix' the problem, but maybenot.. since MBB is right, this is probably a dominance thing.. myfemale constantly humps my neutered male we're saving toget her fixed and hopefully it will calm it, but i dont expect it tototally stop..
do you know that the sex of the other bunny is male?? ifyou're not sure of either one maybe you should take them to a vet andget them checked.. or you might have babies on the way!
How old is the female? Sometimes theywill hump when they reach maturity and want to breed. Gettingher fixed might help it, but then again it's also a dominencething..... you just never know.
Well fixing the female might help, but it's not acertain thing. But it's recommended to fix her anyways due to the highrisk of ovarian cancer and other problems.