They have a habit of sneaking onto property that does not belong to them and doing their best to establish a permanent presence.
They have a habit of bringing with them dangerous items liable to harm, or even cause the death of, the inhabitants of the place.
They never ever accept any responsibility whatsoever for any damage they've caused.
They've been seen on every continent except Antarctica, are serious pests, and have killed off several entire populations.
They have a habit of eating their own young if disturbed.
They tend to be not quite hairy enough, often having naked tails.
Yes, that's right, you've got it. Something murine is a rat or a mouse.
Well, what else might it be?
This is a Norway rat.
Spot the frippet: something murine. This word comes from the Latin mūrīnus, to do with mice, from mūs, mouse.
PS Adèle Geras has alerted me to the fact that Murine is a sort of eyedrop. Still, I don't suppose it could be made from rats, could it.
No. Of course not...