Answer: There are actually a number of night feeding pests. Snails and slugs are high on the list, followed by cutworms and mole crickets, and the list goes on. I'd go out at night with a flashlight and see if you can catch the culprits in action. Go out at various times (dusk, 10 p.m., very early morning....) Once you figure out who's munching you can determine how best to control them.
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