This movie I am looking for is in the 80's. There is a little boy involved and he sees his teacher eating a disected frog in his classroom. He also goes in a cave and sees his teacher with other people. I think the boys name is david and he is 10 years old. Thanks

There is already a post on this film

https://www.askmehelpdesk.com/movies/alien-teacher-invasion-79344.html