Many toys that will be opened by little ones during the holidays will need batteries to operate. But those batteries pose a serious harm, Consumer Reports warns. A lot of these gadgets and gizmos are powered by button batteries or coin cell batteries, which are small and powerful. It is so small, in fact, Consumer Reports said several are smaller than the size of a Cheerio. It's clear that the batteries are a choking hazard, but Consumer Reports said there are other hidden dangers if one were to be ingested. RELATED STORY | Great last-minute toys that kids will love this holiday season"Fluids in the body can activate the batterys electrical current, even in a used or dead battery. A battery can burn through a childs esophagus or throat in as little as 2 hours. In contact with stomach acid, a battery can leak corrosive elements, too, posing the risk of poisoning. And if a curious child puts a battery into his or her nose or ear, body tissue there can be damaged," said Consumer Reports. Swallowed or inserted batteries often require surgery to remove them. And it goes beyond toys: These small batteries are commonly used in household items like remotes. RELATED STORY | Consumer group warns about dangerous toys ahead of the holidaysConsumer Reports bought 31 products that run on button batteries to assess their safety or lack thereof. "Ten out of the 31 products we bought had dangerously accessible button batteries, and many more lacked clear warnings about the risks they posed," the group said. Consumer Reports said before gifting toys or any other battery-operated items, you should test them to make sure the battery compartments are not easily accessible or flimsy.