I can say for sure that the security sensors do not hurt the fish. I have carried live fish through airport security and I can promise you airport security has much more powerful systems than Walmart. I will say however, that you don't ever want to admit to TSA that you have live fish, they won't let you bring them through. They have to be smuggled, either inside carry on luggage, or bagged and in a large styrofoam cup with a lid and a straw, and with fresh water poured on top of the bagged fish. (this is in case TSA makes you drink out of the cup to prove it isn't hazardous etc.) LOL Where there are good looking fish, there is a way to bring em home!