Grasshopper mice live in the United States and Mexico, so don’t worry, fellow Europeans — the Atlantic Ocean is here to protect us (and our scorpions) from these fiendish, carnivorous mammals!These rodents are tiny! The southern grasshopper mouse is only 3.5 to 5 inches long (that’s 8.9 to 12.7 centimeters). But don’t let that fool you into thinking it’s like any other mouse out there in the world. They are deadly, just not to us people.
https://www.youtube.com/watch?v=XNxqIYLthus
There are plenty of videos like this on youtube where you see the mices eating the chicks starting from the bottom or from the head, with no reaction from the birds and the chicks themselves...