The impending mouse horror

OK, I wouldn't be so concerned about "Gene turn-off makes meek mice fearless" (New Scientist):

The research found that mice lacking an active gene for the protein stathmin are not only more courageous, but are also slower to learn fear responses to pain-associated stimuli, says geneticist Gleb Shumyatsky, at Rutgers University in New Jersey, US.
In the experiments, the stathmin-lacking mice wandered out into the centre of an open box, in defiance of the normal mouse instinct to hide along the boxs walls to avoid potential predators.

...if it weren't for the fact that I still have nightmares about this story from earlier this year:

The videos confirm that mice are taking on the chicks, biting them over and over until they die from loss of blood or infection. Wanless, an invasive-species biologist from the Percy FitzPatrick Institute of African Ornithology at the University of Cape Town, South Africa, vividly recalls watching the first videos. "It was carnage. Chicks half alive, with massive gaping wounds and guts hanging out."

...and this older story from Scientific American:

Scientists may not be able to build a better mouse trap, but they have learned how to build a better mouse. Princeton neurobiologist Joe Z. Tsien and colleagues from MIT and the University of Washington recently created a strain of brainier mice, dubbed Doogie after the teenage genius depicted on TV, by manipulating a single gene.

Superintelligent, bloodthirsty mice with no fear. Lab breeders, please stop now before it is too late!