I'm posting this thread for various questions I have. All of which are behavioral. I didn't want to post two or three threads, so I was going to make a master post. New Rescues: Background: I've had a pair of (presumably) brothers who turned a year old in December and are in great health. They drink, eat, and sleep normally during the day. I got them back in August because I had just lost my heart rat and wanted to redirect my grief into helping homeless rats. These two were free on Craigslist, because the ad said the rats caused a severe allergic reaction. However, when I went to pick them up, the guy didn't seem even remotely upset that he was rehoming them and didn't give me much information. I mean, he gave me the box they were in, a extremely brief chat about them, and drove off and left. Not even a look back to us. From their behavior, I'm positive they were either abused and/or severely neglected because they were terrified of my hands and have bitten me on multiple occasions. They were in good health, but this man may have left them completely alone for up to four or five months, assuming he got them when they were babies, touched them once, and then never did again. 1. They are timid angels during the day. Come night, for whatever reason, they refuse to cuddle up and sleep with any of the other rats and instead relentlessly pick on my other rats, save for Grumpy (because he doesn't take their crap at all and will immediately rear up if someone looks at him wrong). During cage cleaning time, I've noticed bites and scratch marks (deep/wide ones, not indicative of accidental scratching during play time) on every other rat, but never these two. They have woken me up at night because the rat they're picking on is so vocal (and I've caught them inches away from the rat who was squealing). The cage is also next to my bed, so they're not that far away from my head. Upon these discoveries, I get my temporary cage out and put them in there for the night. What sort of bothers me is Owen would do this, then stopped. There was a lull with absolutely zero issues. Now, it's Peter picking on everyone. My current rats have never picked on them relentlessly and have always been extremely accepting of them. I spend most of my time in my room, so I usually have a pretty good understanding on my rats' daily lives. I know the first suggestion is to separate them and neuter them. I've separating them. I'm looking into a better rat vet local to me for a neuter. For now, I'm just looking for theories as to why they've made this change so that I can avoid it in the future. 2. Owen bit me extremely hard. Like, it almost wouldn't stop bleeding and there's about an inch-long, deep cut in my right index finger. His top teeth got my knuckle and I'm sure he must have hit bone because it hurts like... well. He's bitten me before, but he and I had worked together very well and haven't had issues since when I first brought him home. I'm pretty sure it's because I stuck my hand into the hide and startled him (I was saying hello to the rat I could see and wasn't aware that he was in there). But, I know I've done this one or twice before and have never gotten bitten. I don't try to. 3. Owen and Peter are now picking on the babies I've had for about three-ish months. I waited until the babies were at least ten weeks to intro them and intros went fabulously. No one blinked an eye or even cared there was babies among them. Sure, they did the typical thing of sniffing the babies and flipping them, but that went fine with no aggression. Now, all of the sudden, the pair are hounding the babies and making them scream at night. My black rat, Luci (male), is now quite large, but he's a softie. He's a little timid as well, but he doesn't have a mean bone in him. Arthur on the other hand, is still smaller than Luci, but he is growing. He seems to be picked on the most. I think my babies are scared of them because they'll squeal at the sight of Owen and Peter, unfortunately. As mentioned before, Owen and Peter have been removed from the main cage into a temporary one. 4. As mentioned before, I've been bitten on numerous occasions. A couple are Owen and Peter straight up walking up to my hand and biting it, completely unprovoked. I was maybe moving poo into a litterbox, readjusting fleece, filling their food bowls, etc. Maybe my hand resembled a scary monster, but I was deliberately careful not to go over them, near them, or anything unless absolutely necessary. I'll gently ask them to move if I have to, but that's never provoked a bite. I guess the sum of all of these questions is... Why the sudden change? I find myself to be fairly good at reading situations and analyzing why I got bit or why my rats have done something they did, however Owen and Peter stump me. My grandmother has seen the bites I've gotten from these two and is very adamant on rehoming them, but I refuse to. At this point, I may buy a single-level critter nation and make a home for those two. I just don't want to stress out my babies and stress out my nearly two-year-old rats. Do I continue to handle and interact with them, even though another bite is pretty much guaranteed? I don't want to neglect them, but with how much they bite me, I'm honestly a little timid to interact with them. Out of cage time would still be a thing, but I don't know that I'll be so hands-on, especially if I can receive unpredictable bites. I refuse to rehome them because I want my home to be their forever home and I don't want someone else encountering this same behavior. They may not be as "okay" with getting bit or unprovoked behavior. I'm not okay with getting bit, but I can and will tolerate it. I have birds, so I'm used to having my hands having holes in the them.