"No blood, no foul"?

A Look at Rat Cage Dynamics

When it comes to rats arguing, the advice you may read is “no blood, no foul”, suggesting that rats that tussle without injuring one another enough to draw blood are doing no harm. I believe this was once said on the forum of the National Fancy Rat Society, UK, and has since been repeated on every rat care platform across Facebook and beyond.

The origins of the statement have to do with rat introductions. That is, if you introduce adults to babies, for example, it would not be unusual to see the adults pinning the babies (though I don’t always see this with my own rats). You are very likely to see the adults grooming the babies, which may be a way of strengthening the bonds between them by creating a scent that is in common with the group. I do see this with my rats during introductions and also when a doe comes into season, though the behaviour of does in season requires a whole other posting!

Allogrooming is a normal behaviour, but as some experts have pointed out it isn’t always a peaceful act. S. Anthony Barnett describes in his book The Story Of Rats, this same kind of grooming by bush rats, which can be a simple case of nibbling, but it can also be “holding the other rat down while tearing out chunks of hair”¹. Ripping out chunks of fur may not draw blood, but it’s very unpleasant for the rat losing the fur. If one of my rats is frequently being too expressive in his or her opinion about another, I don’t breed from that animal. If she or he does it too much, I will rethink the cage dynamics. I can go a year or two (or more) without problems, then find myself with a situation I need to sort out! Sometimes, it’s just a matter of restarting introductions.

The statement “no blood, no foul” is true only if the arguing takes place during a very limited period of time, for example during the first hours or even a day during introductions.