I'm trying to identify a show that I watched as a kid in the early '80s. I feel like it might have been British, and I could swear it was on PBS on a weekend morning.

I vaguely recall ~2 kids (maybe 1 girl, 1 boy), around 12, stuck in a spaceship (but on Earth I believe), trying to hide from the aliens that moved around their ship through chutes. They looked like stumpy cephalopods. I recall the kids trying to hide from them. I think maybe they were friends with 1 of them.

Does this sound remotely familiar to anybody?