Aggression: the rat edition

Since we’re talking about aggression, I have to tell you about our rats. We’ve had the older trio for a year now and the young once arrived in the beginning of March. They could move into a shared cage after two weeks and during that time we had opportunity to observe plenty aggressive behaviors (see video below).

The truth is that we know very little about the social life of rats. And whatever we do know is not 100% applicable to our situation because they looked either at wild rats, or laboratory rats. At the moment we have 6 rats and while we do let them out to roam for 2-3h a day, their territory is much more limited and they live in a much smaller group than wild rats.

What we do know is that rats – as opposed to dogs – do establish dominance hierarchies which are then maintained through a wide range of social behaviors (such as grooming, sharing (stealing :D) good), huddling, sleeping together, submissive posturing and marking). In this case it is also true that once stable relationships are established, the frequency of aggressive behaviors drops a lot.

At the same time, we probably don’t know more than we do just because our experience of the world is vastly different. Two crucial components for rat communication are vocalizations and olfactory communication – we simply can’t hear most of the sounds they make (the frequency is too high) and don’t even get me started on our sense of smell, or rather lack thereof.

Our rats met for two weeks only outside, first on a neutral territory (in the bathroom) and then in my room. We swapped the dirty bedding between their cages so that they could get used to each other’s scent.

And how did we know that they were ready to move in together?

  • the frequency of aggressive behaviors decreased (chasing, fighting, vocalizations, forced grooming etc.)
  • the young rats would come out of their hiding places much faster after conflicts
  • the young rats started eating when they were out with the old rats – after a while they started eating side by side (we scatter feed)
  • they all just started hanging out next to each other, on us and in the cages

One more important fact: during the two weeks no one ever got hurt! I admit it was hard to watch sometimes through the eyes of a dog trainer but I trusted a professional’s advice (Klikk patkányok/Sunny Side Dog Behavior) and there truly was no need whatsoever to intervene. After all aggressive behaviors are a natural part of communication – both in rats and in dogs.