Answer: I suspect your broccoli plants are being attacked by little green cabbage worms. They are difficult to see because they are the same shade of green as the broccoli leaves but you'll probably see frass (bug poop) beneath your plants or on the leaves directly below where they are feeding. Bt (sold as Dipel or Thuricide) will control them and is safe to use on your veggies. Best wishes with your broccoli.
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