KMC Forums - Can you find these film titles?????

I’m looking for 3 film names.

I remember the films from my childhood and I’m 98% sure that they are not TV programs. I however can supply helpful chunks of the plot but so far the IMDB and Google have yielded no results. The information is best guess.

1. British films from 70’s I think. Little grey balls from space. They are not ships as in one scene the boy drops the ball into some milk and it drinks it. I think at the end 1000’s of balls come to save the one that was lost on earth.

2. British film again from 70’s I think. Power Plant goes critical. The local towns and villages are evacuated to a safe distance. However one family realise there son is missing. He was doing something, which I can’t remember (may have been fishing but that’s a guess) the authorities are reluctant to send a team in but it’s a race in time to either rescue him or stop the plant going critical. (Which is what they do just in time)

3. American film from around the 70’s. This involves killer ants and should be the easiest films to find. Scientists get trapped in a dome by the ants. They keep storming the dome and run suicide missions to cut the electricity and generators of the dome. The scientist’s defence is blue and red die, which kills the ants. They however mutate and come back as different colour ants. In another scene a farmer make a moat around his house. He fills this with petrol. When his hoarse starts to be eaten, he lights the moat. The ants sail across on something.

Thanks for the help!