Helping my grandpa keep bugs out of his garden

When I was a youngster, maybe 6 or 7 years old my grandpa wanted help getting the stinkbugs out of his garden. He gave me a metal coffee can with about 3 inches of gasoline in it and told me he would give me a penny for every bug I killed. I went through part of his garden catching stinkbugs and probably other bugs and putting them in the can. When I got hot and tired and the can was about full I took it to him and showed him. He looked in the can and acted like he was counting and pretty soon he nodded, set the can down and handed me a $5 bill. I was amazed at how fast he could count.