Alien movie where some of the aliens were previously abducted kids

Question

I remember watching a movie where, in the beginning, the government gave a seven kids or so to aliens in a UFO. In the midst of the abduction, one runs away and escapes abduction. I don't recall too much of the plot but at one point there is an scene where people have an alien behind a piece of glass, but they are unable to see it because of green smoke. The people try to talk to it and it is angered and bangs a crablike appendage against the glass. Eventually one of them goes into the room where the alien is and discovers that it is actually a previously abducted child (Lumier, I think) who is hooked up to a machine and fed drugs by the abductor aliens. This may be another movie but I think at one point kids start repeating numbers which signify how many children the aliens want to abduct.

Answer 1

Could this be Torchwood: Children of Earth?

The plot of Children of Earth deals with aliens demanding the Earth's children, and a related earlier conspiracy 40 years ago; as such, Torchwood is pitted against the British government when the government attempts to conceal its past actions and concede to the present-day aliens' demands.

You can see the scene you're referring to below.