Half of Americans drink a soda every day. But when people grab the can, not many clean off the lid before taking a sip.So we decided to put soda cans to the test and measure the yuck factor.Pop the top on your favorite soda and you expect to swallow sodium, sweeteners and caffeine. But, some other stuff, you'll never find on the label, could be lurking on the lid.So KEYE TV decided to find out exactly what your lips are touching with each sip. From Bastrop to Leander and Georgetown to San Marcos we collected 15 cans from inside convenience stores, gas stations, grocers and pharmacies. We saved our last quarters for the vending machine right next to the KEYE TV newsroom.We took our can collection to Austin Community College Biology Professor Felix Villarreal to find out what's living on the lids. Some of his swabs quickly revealed the grime that could be going in your mouth. But, even the cans that look clean could be covered in bacteria. They could be completely contaminated and you wouldn't be able to see anything, said Professor Villarreal.Our samples quickly grew into these yellow, white and fuzzy dots. Each is a different type of bacteria or fungus.100 percent of all the cans we tested had some bacteria on them, said Professor Villarreal. Some had one organism. Some had thousands.The worst offender came from a gas station. That's a bunch of bacillus, said the biology professor.That's a bacterium that lives in dirt. It could have gotten on the can in a delivery truck, warehouse or at the gas station. It's not dangerous, but it's not clean, either.It's just packed, said Professor Villarreal.But, what may surprise you is that the cans that looked the dirtiest did not always have the most germs.One can we bought at a convenience store looked clean, but our tests revealed it had more than 20 different bacteria and molds growing on it. They're not likely to get you sick, but there are other issues.There's kind of a disgust factor when you think about it, said the ACC Professor. The most concerning find came from a Dallas gas station. CBS affiliate KTVT is doing a similar test and found the dust on the top of this energy drink contains coliform. Which means something from the toilet was living on the can.It's something from the rectum, would be a better way to describe it. It's coliform, so it's something that lives in human and animal large intestines, said Dr. Cedric Spak. The Infectious Diseases Specialist at Baylor University Medical Center of Dallas says it could have come from someone who didn't wash their hands after using the restroom or from a rat in the warehouse. Either way, he says these germs are all around us and most healthy people have nothing to worry about.It's not that bad and it's not that surprising at all, said Dr. Spak.Maybe not to him, but our test results didn't sit well with the lunch crowd on South Congress.I don't even drink out of a can anymore, for that reason, said one woman.Another woman said, I'd probably wipe off the rim and keep drinking it anyways.A lot of people do just that. They wipe off the lid with their shirt or a napkin. But, both of our experts say that's not the best way to keep from swallowing bacteria. They say stick the top under running water and that will get rid of many of the germs.Consumers can also buy covers for cans. Soda Straws and Can Caps will keep lips off the lid.The American Beverage Association had this response to our rest results:Our industry is committed, first and foremost, to the safety and integrity of its beverages and their packaging and meets, and often exceeds, all government health standards in bringing its products to market. As with all foods consumed directly from the manufacturer's packaging, consumers should take reasonable care to ensure the packaging has not been damaged or soiled once in the marketplace. Maureen Beach, Director of Communications, American Beverage AssociationBy Bettie Cross