Nicotine is a natural insect repellent, and will keep mites, fleas and ticks off of the baby birds. Besides, birds have way better instincts than we do. If it was so bad for them, you'd think they wouldn't want to have babies near it.

You can soak cig butts in water and make a plant spray to keep aphids off of your roses. That's what my grandpa used to do and it works great.