A recently conducted Experiment produced mixed results.
Four female GCSs sequestered on nest boxes incubating eggs. On the right is a wild boar woman in a cage, and an exit to the outside world on the left. The intruder has to run between the spiders to escape, but there is a back-up cage trap set to recapture her if required.
Resulted in this.........
One of the females abandonned her eggs to deal with the intruder while the others spammed gobs of webs. Naturally, it was the female sitting on the most eggs that decided to attack the boar woman. During combat she also fired 6 webs, with one web ending up on the cage trap, (not shown in pic 2, but is visible in pic 1)
And, with the intruder dealt with.......
The female returns to her, now ruined, eggs.
Accidental stuff learned during this;
Animals will use nest boxes even if they are forbidden,
Dorfs will generate a job to collect eggs even while nest boxes are forbidden.
(Might try 'Hiding' the nest boxes next time, see if that makes a difference).
Edit: Hiding the nest box makes no difference either; the GCS will still use it and the dorfs still collect eggs if you are not quick enough to forbid the eggs.
Also, made some mods to the experiment and learned a few new things.
Dug a channel to separate the GCSs from the wild boar woman test subject, GCS spammed a lot of webbing, but stayed on their nest boxes, a nice improvement. however learned that webs can span open space and the weaver cannot collect webs 'hanging' in space. This will require yet another change to the experiment.