I have 2 young pacmans and was having the same problem. My female wasnt home for more then a couple days so we decided to try her in a smaller container for feedings. Right away she was fine with this and ate a large meal of 4 crickets. After a few feedings in the container she has become very comfortable feeding like this and knows the container means feeding time. I will gradually increase the size of the container I am using so she gets used to "hunting" larger areas. My male pacman is about a month older and is more accustomed to eating in the 10 gallon tank. I was finding that a good misting of the substrate before feeding helped him but have since started feeding him in a container as well because he was still eating the substrate too much for me to be comfortable.