Bait all year round. I put my feeders up so I can shoot them side on, that way I can shoot them with anything, air, lr, HMR, .410, 12g, without damage to the feeder. Cover the feeder in something the squirrels can't chew, if it runs out of feed they'll try and eat their way in. Use whole wheat from Mole Valley, it's about £8 for 20kg.