The reason why I am replaying the campaign is that I got a new computer, so I am working on a new formicarium (which I don't mind doing). But the problem is, one of the wolf spiders (one of the medium/small ones) the scientist drops is getting stuck in my nest holes. On the minimap, it is shown to be on the surface, and if I go into photo mode and rotate my camera I can see it in one of my nest entrances. I have attempted the challenge multiple times but every time it gets stuck in different holes. It doesn't attack my ants, and my ants don't attack it. It sometimes twitches slightly but other than that it doesn't move at all. It appears the same spider keeps getting stuck (based on size).
Note: On my fourth try a spider actually did not get stuck at all. I don't think I did anything differently and I was able to complete the challenge.
Note: On my fourth try a spider actually did not get stuck at all. I don't think I did anything differently and I was able to complete the challenge.