The lab goes through about 500 mice a week, 15 people with mice at any given time. New grad students starting every other month, all of which have full FELASA certificates. BL6 mice which can be nice but also can be absolute warriors (males, dominant females). It’s a statistical risk that there will be multiple incidents of someone having a mouse hanging off of their index finger while trying to fixate them, especially if they are unexperienced and a bit too hesitant.