Yeah, if there's a downside to free ranging, that's it - they will get in your garden and eat what they want. So intead of fencing my chickens in - I fenced my garden in. Yesterday the gates were left open and they all got in and were eating the new little bean and pea sprouts that had just started coming up and munching on the lettuce. I was out there "shoeing" to no avail - they wouldn't budge - I started trying to feed them biscuits and other treats to get them out but they just ignored me like "Nope, this is better - sorry we're not leaving".
