It sounds like tall tales to a large number of people today, but even in my short life of only 30 years, the change is huge. I remember being a kid and windshields being covered in insects after a 30 minute drive. I remember turning a light on outside at night and the sides of the house being swarmed luna moths, hordes of bats swooping by and grabbing everything they could, and possums scattering away from the porch. I'd walk around the lake and see snapping turtles lazing about in the sun. Fish splashing in the water. Walking in streams, there'd be so many crayfish that they'd slip inside my sandals and I'd accidentally crush them.
Now I see nothing.