Excellent article, all good and easy things to do. Personally, we've swapped our lawn for a veggie garden and in it, we don't use any pesticides or herbicides, and we've mulched heavily using Chip Drop.
You wouldn't believe the explosion of different types of insects we've seen since adding that mulch, worms and grubs and millipedes that used to be rare are now everywhere! This has in turn brought more birds, including an annoying crow who repeatedly yanked out my pepper seedlings to get at tasty morsels below. We ended up having to put mesh from old window screens around them, which thankfully was enough discouragement.
Our cat also gets supervised yard time, and my fiance has managed to train her to respond to "inside!"
I'd say the one on the right looks pretty close for harvesting, though you could probably leave it another day or two. My general rule is I pick them when they're as long as the distance between my thumb and pinky when outstretched (gently, not as far apart as they can go), but obviously hand sizes vary!