Thistle is a fast-spreading, difficult to control perennial plant. While birds may like it, people walking barefoot through a lawn generally find its prickly leaves painful. Thistle has a lot of underground roots and is difficult to kill either naturally or with chemicals.
You can stay diligent with your Speedy Weedy (weed pulling tool) and pluck it out as you notice it. You might even try filling the hole left behind with some all natural Burnout to try to kill the root a little better. Adding one or two additional Natural Weed Buster applications per season can help give extra Thistle suppression without chemicals. If they really bother you, a spot chemical weed control spray in the fall or spring will work best.