Hi there, I’m not very familiar with overly aggressive bunnies, but I do think you should put bonding on hold for a while. This negative behaviour keeps being reinforced everytime they have another fight. This might be completely wrong, but I would suggest starting from scratch. Remove them from each other’s sight and smell, to different rooms if possible, for at least two weeks so they can forget their fights. I actually think you should seperate them completely for another month, as their hormones can stay active for two months after spaying. Then I would put their cages next to each other again, right from the start.

The burrowing at the cage is kind of normal, give it a week to see if that gets less and if it does, great! Lying next to the cage of the other is also good. Remember not to put the cages so close that they can hurt each other through the bars at all. I would keep them like that for a month or two even, and note their behaviours. Some bunnies calm down with time, others just get more and more angry. Have you tried swapping them to each other’s cages every day? It’s good for them to get used to living with the other’s scent. Remember another thing, if the bathroom doesn’t work, try the empty, dry bath tub. If that doesn’t work, try an xpen on the kitchen floor, even outside, as long as it’s completely new to each bun and you can still quickly stop any fight. If something’s not working, change it. Maybe put a neutral (not smelling of either) litterbox with some hay in there with them, give them something else to focus on than each other. Try talking to them in a soothing way or even singing to them while petting them calmly. It’s important for you to be calm during bonding, because they will pick up on your stress and associate the other bunny with that. This last bit is the hardest part of bonding, for me.

If all else fails, see if you can get some Pet Remedy to relax them a bit. I’m actually soon to bond three pairs together and have started them on a bit of pet remedy, as there have been quite a few fights in the past.

Regarding fighting and nipping: A little nipping is okay, humping is okay (keep it to 5 seconds maximum then gently remove the top bun and put them alongside each other, you could even try gently petting the bottom bun if she doesn’t seem to like the humping). If there seems to be too much humping going on, gently stop it before it starts for 20 minutes or so, as excessive humping can make the humpee angry and lead to a fight. All of these things are okay as long as they don’t lead to circling or chasing. Always stop circling or chasing as these two behaviours usually lead to a full blown fight. You want to avoid a full on jumping in the air, ripping out each other’s fur fight at all costs as this sets your bonding back by about a week each time. Also don’t allow reverse humping (humping someone’s head) as a bite down there can be quite horrific.

Always end a bonding session on a positive note (this can even just mean they’re ignoring each other) and give them each a small treat so they start to associate each other with good things. Keep bonding sessions short at first, 15 minutes max until you see improvement. If you do stress bonding, try stressing them on a car ride, then straight back in the cage for the first two or three times before putting them in neutral territory after the car trip.

Even though I do believe any two buns can be bonded given enough time and patience, not everyone has the time or patience required to do it. My advice is not to give up too soon on them ever being bonded. Bunnies can hate each other today and three days/weeks later, they’re inseperable. Just focus on the positives and try to avoid the negatives. Sorry for my long answer.

Females tend to be more territorial so you have my sympathies. I can’t imagine bonding two of my Olivia!

You’re on the right track by doing stress bonding. However, from research and personal experience, I definitely agree with kitty, after the stress bonding, do not put them together. Stress bond, then let them go back to their separate houses. I found mine would be extra aggressive when together right after the stressing. Like they were taking out the stress from the car ride on each other.

I definitely think you should just keep them seperate now for at least two weeks, preferably a month. It’s just very important to give them time apart so they’ll forget these fighting experiences.

Then I still think you should swap their cages every day or at least every two days. I should have mentioned that you can expect the loo habits to go out the door, it’s only because they’re trying to spread their scent over the other bunny’s scent, thereby mixing their scents together, which is exactly what you want. They’ll probably tend to mark the side of the cage that’s closest to the other bunny with poops and pee. It’s like the border between mine and thine and whoever marks most, wins. I like to call this the poop wars, trust me, with three different sets of buns in my house at the moment, the poop wars are in full swing. This is okay, when they’re bonded, their good litterbox habits will gradually return in a month or two. Bunnies generally like to be clean, this is really just to try and exert dominance in a very passive aggressive way. Perfectly normal.

Okay, bath tub is out, try something else. What actually worked for me and it’s a technique I still use although it’s probably a bit dangerous, so don’t do it alone, is to put them both on the dining room table. It’s smooth and slippery so not easy to get a good grip on, kind of a good stress bonding without any borders confining them. I put the table against a wall, so there are only two or three sides where they can jump/fall off of. This is the dangerous part, and the reason you need another person to help so they don’t accidentally get hurt. Each of you keep a towel handy in case you need to stick it in between them when they’re getting aggro. I put a litterbox and some water on the table as well and if it’s going well, I’ll feed them their veggies on there, also.

I know what you mean by both being sweet on their own, one of my girl buns is the sweetest thing with humans, but such a little aggro thing with the other buns. I’m still gonna bond her and her mate with my other four, it may just take a bit longer.

I think you can start the stress bonding after the month is over, try to do that every day then back in the seperate cages next to each other for a week or two and see if there’s progress in their interaction between the bars. If they seem to be making progress, you can attempt another meeting. Basically you have to let their reactions steer you. Sometimes bunnies will be fighty the first 20 minutes of a session, in which case it’s good to make the session last longer so there’s more happy time than angry time, sometimes they only start fighting after the first 10 minutes, in which case you’ll want to keep the sessions shorter than that in the beginning, give a treat after 10 minutes and stop. Rather maybe do two or more shorter sessions a day. Again, avoid full blown aggression at all costs.

Top tip: Do bonding sessions in the middle of the day, when they’re in nap-mode instead of early morning or evening, when they’re fully awake and alert.