They use ground shipping in the same 1 inch insulated cooler type styrofoam that companies ship frozen food in with lots of dry ice. Why would anyone save a couple bucks on dry ice then spend 2-3x as much on overnight shipping? If you look at the price per rodent, they are higher than RP or MD. That partially makes up for free shipping. The free shipping also is only in certain areas, they say cheap shipping to other areas. Never had ripped bags from them. I always get ripped bags from Mice Direct. I've been ordering from them for 4 years and never had a problem.