It could be fracking.... This is a relatively new procedure, and probably needs more studies. Since it can mimic earthquake like activity, and if they did it on a regular basis, that could explain the animal behavior for such a long period of time.
It is in Ohio: http://www.cbsnews.com/news/fracking-linked-to-ohio-earthquakes-officials-say/
My brother is a petroleum engineer and began working in Ohio in 1979 with Halliburton, and they were fracking even then. The hullabaloo over fracking is recent, it’s been going on since the 1940s with Standard oil fracking in Oklamahoma.