Just want to second what others have said about not splitting them up. Each time you split them up and put them back together it's like meeting a new piggy again.

It may take much longer than an hour for them to decide on dominance. The rumbling, chattering etc is all part of that. It might go on for ages and then suddenly stop, they might be fine for ages and then will start to challenge.

When I'm bonding I use the bath with a sheet down so they're not on the cold plasticky bit, with a bit of food down in the middle. There will be abit of bum sniffing, chattering, rumbling, yawning etc... but that's normal. If it's continual and their hair's on end watch them closely. If they 'lunge to attack' once or twice I would stay and watch them, if they draw blood or are going for each other multiple times I would split them off and probably admit defeat. If things appear to be going well then I would completely disinfect their hutch or pen and keep it minimal. In my experience using multiple hides doesn't work as mine have claimed a hide as their territory and all hell broke loose in the morning. If they only have 1 bedroom then they should cuddle up to keep warm and help the bond along.

I know it sounds mean but if they don't seem to be aggressive towards each other but aren't cuddly with each other so you're not sure about the bond. Bathing or a short trip together in a carry case in the car will help to make or break a bond. I would use this as a last resort if you really aren't sure though.

If it's male and female you should have a pretty good chance of bonding them to be honest, unless one of them is particularly aggressive and dominant.

__________________
Adopted by:

Ginge - Abby guinea piggy
Bubbles - English crested piggy
Mackenzie - English crested piggy
Skit - Standard (but cute) piggy
Max - Ragdoll x cat
The Rainbow Fish
Rest in peace my lovely furfamily that are no longer with us.

What you describe sounds normal. Rumblestrutting could also be the fella telling the lady he's so sexy.

Unless they fight and blood is drawn you need to commit to the bonding and bond them and not seperate them at all - they need to stay together no matter what.