Is my rabbit confused or am I?

Question
We bought a rabbit in the spring (2007) that we believed to be a male Rex. When he was around my brother's rabbit (definitely a male) he attempted to dominate him by mounting him so we became more sure he was a male. We have not had him neutered yet and periodically he has "mood swings" that seem almost like a female. He has the large fold of skin under his neck and begins to lose hair and pull out tufts of it and becomes slightly aggressive (not enough to worry us, but enough to cause us to keep him away from non-family since he is a house-bunny and will bite at those times). He acts as if he is trying to build a nest out of any stray piece of clothing he can get his paws on. He will do this for 3 or 4 days every 3-4 weeks or so. This is our first rabbit and we are wondering if it is normal for male rabbits to exhibit what seems to us to be "nesting" behavior.

Answer
Hello,

Before going any further -- have you physically checked the sex of your rabbit? I would start there as the signs seem to indicate he is really a she.

I am going to include a link that includes not only instructions, but pictures as well: http://www.debmark.com/rabbits/sexing.htm

Once you let me know the sex for sure, we can go from there.

Thanks for your question!