500
Sometime in November, a man takes his dog for a walk in the woods. When the man comes home with his dog, he is very annoyed about something. However, this gives him an idea for an invention. Today, this thing is used in lots of clothing, shoes, and sometimes bags. What was the invention and what gave him the idea for it?
The invention was Velcro, and the burrs on his dog's fur gave him the idea.