For me, I started thinking about the cost and the smell every time I had one. I quit cold turkey a few weeks later and felt grossed out every time I had one after that. I quit in 2009 and haven’t had a cigarette since 2010.
Cigarettes smell really disgusting to me now.
Those holes are almost certainly made by a woodpecker. That probably isn’t the real problem though. That wood is almost guaranteed to be infested with insects.