That rarely happens unless the gators have been fed by humans or the human is walking a dog. They are fast on land but only for a very sort distance, but they are very fast and very lethal in the water. Most people who are attacked are in the water and typically have ignored warning signs that gators are present. For the most part, gators are on the land trying to warm up when it's cool, which means they are in lazy mode. Humans are too much work to be a source of food. However, dogs are easy. Many people who are attacked on land were trying to save their dogs. Don't get too close and don't ever walk a dog in an area known to have gators. Dogs are like bait to them. Of course, there are always stupid people who get too close for a photo or who try to feed a gator.