Plus their tiny little feet are way too weak to get a Zippo going.
Except that it's not, really.
It turns out that not all animals mind: Some birds are purposefully seeking out cigarette butts to line their nests because the nicotine that cigarette butts absorb while you're smoking them is pretty effective at combating the kinds of mites that plague bird nests. Researchers discovered this after planting heat traps lined with both smoked and unsmoked cigarettes butts in the nests of common house finches and sparrows. After a mere 20 minutes, the scientists found that traps with unsmoked butts had caught roughly twice as many mites as the traps with smoked butts. So, if anything, rather than disposing of your cigarettes properly, just toss that bird a fresh smoke every once in a while.
You've come a long way, birdy.
Of course, being a general bummer, the scientists also pointed out that, while protective and beneficial in this one very specific instance, nicotine is still generally poisonous as all hell, so ashing your American Spirits into a baby bird's mouth doesn't count as your good deed for the day. What you can take away from these findings, however, is that even parasitic bird mites are turned off by smokers.