I'm looking for a 1950's movie where there was an alien invasion. They sent mechanical bat-like objects flying around implanting little devices into human heads, and then taking control of their minds. Any ideas?
Possibly "It Conquered the World" (1956). It has the bat thingies but there's only one alien.
The movie you are looking for is Invaders from Mars.
We're looking for long answers that provide some explanation and context. Don't just give a one-line answer; explain why your answer is right, ideally with citations. Answers that don't include explanations may be removed.
Perhaps it is "Zontar the Thing from Venus." Zontar was a bat-like alien who lived in a cave and grew little bat-like things that flew through the air chasing people and implanting what looks like barbed wire in their necks, after which he would be able to control them for the purpose of conquering Earth.