Thank you very much for your question. I appreciate that you were willing to share your thoughts and concerns with us. I applaud you for your environmental awareness. In looking at your history of question submissions to our forum, I saw on 6/20/16 you consulted us regarding destruction of squirrel habitats. On 9/13/22, you shared your thoughts about population declines in our state with respect to Monarch butterflies.

In researching your current question involving night crawlers, I could not find any reports that involved rigorous scientific investigations. I suggest that you do the following:

1). Contact the Great Lakes Worm Watch that is associated with the University of Minnesota. See:

https://wormwatch.d.umn.edu/

2). The following site provides some general information about night crawlers:

https://extension.umn.edu/yard-and-garden-insects/nightcrawlers

https://extension.umn.edu/identify-invasive-species/earthworms

3). There have been suggestions that the rise in jumping worm populations in Minnesota is leading to the decline in night crawler populations. The following will give you information on jumping worms:

https://jwp.cfans.umn.edu/ - :~:text=The project's goal is to: * Characterize,Twin Cities * Duluth * Saint Cloud

https://extension.umn.edu/identify-invasive-species/jumping-worms

https://jwp.cfans.umn.edu/sites/jwp.cfans.umn.edu/files/2021-09/PDF handbook.pdf

Good luck in your learning venture. Please contact us if you have further related questions.