The most common problem you will encounter while keeping snakes, is that your snake does not want to eat. If an adult snake stops eating during winter, don’t worry this is normal. As long as the snake has been feeding well during the summer this should not be a problem. Some snakes will eat all year round as long as the temperature in the cage is high enough. Snakes will not eat when they are in a shed phase. Not feeding becomes a problem with hatchling snakes as they do not have fat reserves. Some snakes eat lizards in the wild and their young have to be introduced to eating mice, this occurs with some Milk Snakes and King Snakes. This is a big problem with White Lipped Tree Vipers. The next problem is that a lot of hatchling snakes are too small to eat a whole pinkie and will either ignore it, or eat it and then regurgitate the pinkie a few days after eating it. Some hatchling Corn Snakes are too small to eat an entire pinkie and need to be fed cut up bits of pinkie. When you buy a snake please make sure it is eating before you buy it. I think it would be helpful for the seller to take a video or picture of the snakes eating, these can then be shown to buyers. There are methods to get snakes to eat such as: scenting pinkie mice with lizards or frogs, cup feeding, tease feeding and a few others. Force feeding is a last resort and should only be performed by an experienced snake keeper.