Are the toilet paper rolls so that they have something to take out their aggression on? (Similar to the way my friend handles her cranky transgendered bunny, who enjoys violently ripping cardboard and newspaper into tiny pieces and then constantly rearranging the results.) Or to distract them with the Shiny New Tube Toy? (This would have totally worked on my roomie's pet mouse, but only after he was terrified of it for like a week. Of course, he was also afraid of toast.)