Odd Male Rat Behavior

Question
Hello! I've contacted you in the past about Skye and Pepper, my young female rats. I contacted a rat rescue, and adopted 4 young males 2 weeks ago, all whom are intact (they won't be introduced to the girls until a month and a half after they've been neutered!), and then on Sunday, I adopted Elliott, a large intact black self male dumbo rat. He's very sweet, and seems to adore human attention. When he came to the rescue, his cage mates were attacking him, so he was separated on his own. He's currently in his own cage at my house, in the same room as the boys and the girls, but there's about a 5-6 foot distance between all the cages.

I handle Elliott first, then the girls, then the other boys. I don't know why, really, it's just how I handle them. Today, my little sister pet the boys, then the girls, then tried to pet Elliott. He was reluctant to let her near, and in the next half-hour, more or less trashed his cage. He pushed just about everything out of it's place, has little hollows in the bedding, and is scrabbling at the corners and making this rapid-fire sneezing sound. He's puffed up to about twice his size (and he was a BIG boy to begin with!), is rubbing his sides against everything, and is leaving A LOT of urine marks as he paces. This is a totally different rat than I've been seeing.

Is this because he suddenly got a smell of the boys? Could the girls be coming into heat? Is this something I need to be taking him to the vet for? Literally, an hour ago he was cuddled on my chest, flat as a pancake and bruxing quietly, and now he's like a little Taz in there.

Answer
Hi Amanda,
It is probably because of the smell of the other boys, and maybe because a girl is in heat. He is demonstrating intense territorial marking and aggressive behavior. The scrabbling is scent marking with his hands, the rubbing scent marking with his side, and the puffed fur and huffing sound is a challenge to other rats, "Make my day!"

If you want to introduce him to other rats, you might need to have him neutered. I don't know if he will continue to be sweet to people or not now, hopefully so. But it is good to continue handling him first before the other rats, and you might have to descent your hands and clothes first too.
Deb