Speaking of Texas, I’ve always been fond of this project
https://www.batcon.org/article/dr-campbells-malaria-eradicating-guano-producing-bat-roosts/
The 1918 bat guano crop from the Mitchell’s Lake “Malaria-Eradicating, Guano-Producing Bat Roost” was 4,012 pounds. Once the bat colony was established, the roost averaged two tons a year.
In the mid-1950’s, rabies hysteria gripped Texas and bats were taken off the State’s protected species list. The end of the bat roost that had once gained the admiration of the world passed without much notice.