The first losses of life on my survey ship were... absurd. Absurd is the only word for it.
We had found a more or less derelict generation ship - the Leif Erikson, last contact about 300 years prior - in orbit around a star not on its route. No working communications or clear signs of surviving crew, but life support systems were running. There had been unusual changes to the hull: additional windows.
We, that is, I sent in a small team to investigate. According to their running reports they found gravity and life support intact, kept in working order by likewise still functioning maintenance bots.
Our team, hah, followed their noses to the gardens, which had completely overgrown, vines spilling over into the access corridor so that the safety door was blocked open. A bundle of cables stood out because it had not been overgrown. When the team followed it, they found its end embedded into a tree. Grown in.
Weird, but not helpful, so the team wanted to look elsewhere.
When they tried to leave the garden, a flock of maintenance bots cut them off. If you think the small ones could not do damage, remember they have welding tools. None of us took it as a dire threat even so, but it turned out that the little critters had been buying time for heavy guns to arrive, the models involved in wall restructuring and the like.
I listened to my crew dying.
We’re no kind of army, so I'll leave further investigations to people more used to being attacked, and better equipped for dealing with it.
If you want to know what I think happened... in the files about the Leif Erikson I found the profile of one of the original crew, someone into trying to communicate with plants. Hooking them up to computers via electrodes. Fits with the cables ending in the tree.
So, maybe the maintenance bot network teamed up with the plants.
And three of my crew ended up as compost.
Absurd, I said.