Pesky winter pests

I hate to even say this out loud, but I'm incredibly lucky when it comes to pests in my veggie garden.  It's not utopia, I get an occasional outbreak of aphids, or a cut worm/ caterpillar type critter damage here and there. But for the most part I have very little pest problems.  Not counting the gopher I fought all summer.  I have not had to use even Neem, or bt (I'm on my phone so I can't check. The one that organically kills. Tomato worms and such).
Every year I keep trying new veggies, and keep expanding my garden. This is the most winter veggies I have ever grown. It's all doing quite well.  In spite of a lot of critter damage.  Most of my peas are doing well, but two spots they have been destroyed, eaten to stubs.  The kale has a good amount of munching but doesn't seem to harm it, and a little on the broccoli. The lettuce and radishes don't seem to be bothered at all.  We have had more rain than the last few years, I thought maybe snails or slugs, but I haven't found any, don't see any bugs, or even any sign of bugs, just holes, or munched leaf edges.
I'm not terribly upset, because there's more than enough undamaged veggies for my family, and the chickens enjoy the rest. It's just strange.  I'm thinking maybe it's because most of the winter veggies are closely related.  Combined with the fact that I have lots of flowers in the summer mixed in with the veggies. I do plant pansies, borage and my calendula is still blooming. But they are far and few, and even though the pansy's are alive, they aren't blooming.  Like I said it's just seems strange that winter is when I have the most critter problems.  
It's time for me to plant my peas for spring. Two of the spots I can plan peas are where the winter pea stubs are.  It's been dry lately, maybe I will sprinkle some diatomaceous earth a few days before I plant.  In all honesty I hate to even do that.  I feel the less interference from me, the better nature can keep the balance.  Then again I can't eat peas if the seedlings have all their leaves eaten off before it even has a chance.  Hum not sure what I will do.
If you can garden in the winter, do you have to take additional precautions?
Thank all happy gardening.

Jen said, "This is the most winter veggies I have ever grown. It's all doing quite well.  In spite of a lot of critter damage.

I am sorry you have not figured out which pests are doing the nibling.

We usually don't have winter pests except for maybe aphids.

I wonder what some winter pests are?  

your weather is similar to mine-- in the winter, when i plant peas, the most common culprit is BIRDS! usually it's a bit dry, the pea greens are moist and sweet, and the birds that normally would be eating my fruit (tanager type birds) eat my pea foliage. The first time I saw it I was speechless.
(they leave the other foliage alone, only attack the peas)

Thank you Tereza.  That may be it with the peas.  I will probably put up a net when replanting my peas. See if it helps. We seem to have more birds then normal the last maybe 18 months.  I didn't see the hawk couple last spring, maybe that's why.??? Anyway thanks