30 years ago, when I moved to Houston, a 1910s-1920s residential area called the Heights was somewhat famous for its fireflies -- though longtime residents woul

30 years ago, when I moved to Houston, a 1910s-1920s residential area called the Heights was somewhat famous for its fireflies -- though longtime residents would tell you they were drastically diminished from what they'd been in the 60s or 70s. By 20 years ago, they were almost entirely gone.