(sorry for the icky part)
As Izzy moved Mouse did too, with a bark, not his usual earth shaking sort, but something that should have been intimidating to whatever he was growling at, he lunged, knocking the table over and snagging the mouse that had been hiding beneath it. With a great shake of his head he killed it before dropping the thing and stepping on it with his massive paw. His large muzzle dropping to sniff at the dead thing after a moment. Content with the deadness of it, he moved over to where the snacks were, and dipped his head into the water bowl.
"Well. That was different." Sarah had never seen him do something so violent to something so small and harmless before. It unnerved her a little. "To be on the safe side..." She drawled as she snagged a clear box from her bag and scooped the mouse up into it. With a few presses of a few buttons she 'locked it away' for farther study later.