yeah, not all rats need company. Some, like Arthur, f*ckin hate it.
I had one named Lily that hated company. She ended up getting goony in the ear and was lopsided permanently, so she resembled a rat ogre.
She was HUGE. Like 9 inches long and solid like a rock, and was always cocked to one side lol.
She had to be put in a tank all by herself because any rats that got near her would get their ass beat. Bad.