Well i read somewhere that the bacteria could possibly make them sick... not 100 percent sure but just to be safe when my babies are done I put them in the fridge in a baggy...Im sure they would last until they were used simply because you can keep them out but if you just leave them laying around they can get the bacteria...I would get a second opinion though since this is just what i read. Also do you ever buy bully sticks from AMD? they are a lot cheaper than pet stores!