1. It smells like rat. Rats secrete an oil onto their skin that gives them their distinct "rodenty" odor. Some compare the smell to that of a warm tortilla, says Ginn, while others compare it to urine. Regardless, it's distinctive. While it's true that the odor lessens after the rat is skinned, and again after the rat is cooked, no amount of cooking can ever completely get rid of the smell.
2. It tastes like rat. The oil rats secrete gives them a distinctive taste as well. Ginn describes it as quite pungent and gamey -- most similar to raccoon or rabbit. Blended with other meats, rat becomes a lot less distinctive, so you'd have to be rather discerning to notice it.
3. It tastes delicious when brushed with a moonshine glaze and barbecued. Of all the ways Ginn has eaten rat, this is her favorite preparation. A close second is smoked rat jerky served on brioche French toast. So, if you happen to be savoring a moonshine-BBQ dish, or think there is something slightly "rodenty" about the gamey and delicious jerky you are consuming, you might want to check the ingredients.
4. It looks like lamb. When it's raw, pinkish/red rat looks very much like lamb. Unfortunately for the Chinese, when ground, rat can look a lot like any generic ground meat. When cooked, rat looks more like rabbit, Ginn thinks, just because of the shape of the cuts.
5. You're in Asia. According to Ginn, rats are most commonly eaten in Asia because of the rice crop. In areas where rats feed off rice paddies rather than garbage, the rodents are considered safer to eat. Of course, it isn't clear whether the rats marketed as mutton in China were healthy, rice-fed rats or sewer-dwelling, garbage-eating, Templeton-esque rats. The New York Timesreports that the arrest announcement "did not explain how exactly the traders acquired the rats and other creatures." Rats are also disease carriers, so when Ginn organized her meal she ordered hers from a company that supplies specially raised, grain-fed rodents to zoos.