A childhood belief about being ill

Ok, when I was 6 or 7 my Uncle got lung cancer. I remember coming into the kitchen and seeing my mum upset, and she told me that he had cancer on his lungs. At least I assume that's what she said, I now know that's what he had, but at the time I must have misheard, aside from the fact that I didn't know what cancer was, because I vividly recall having a mental image of a pair of lungs with ANTS crawling all over them! I was horrified at the thought of such a disease!!!