Day or night, irrelevant. An unceasing flood of drones (e.g. Three of Eleven) that just keep coming with the intent to build a road inside my territory and dying to my towers, then instantly respawning in the corruption. Is this to be expected?
After 2 days I could no longer keep up with them, so they destroyed all my buildings and built their road (I marked it red):
I'm not 100% sure if this is a bug or intended, but an infinitely and freely respawning enemy builder that wants to build inside enemy territory sounds like it. I don't think even on day 22 on Survival I should be fighting this many units (see second picture->1000+ enemies/day).