I am emailing you at 3:30am because I can't sleep. Nothing very dramatic, but there is a mosquito in my room that keeps buzzing in my ear and driving me crazy. So I got thinking, why did G-d create mosquitos? What possible purpose could they serve other than annoying people when they are trying to sleep?
Be careful who you call annoying. That mosquito may deserve more respect than you think.
Indeed, the Talmud has some harsh words for mosquitoes. It says that while all creatures contribute to the grand scheme of nature, the mosquito is one exception. It is a consumer, but not a giver. It survives by sucking the blood produced by others, but doesn't itself produce anything useful for the world. To take and not give back is the exact opposite of holiness.
And yet, a mosquito may in some cases be better than a human being. Because even when a mosquito annoys you or bites you, it is just doing what it was created to do. But when a person annoys and bites, causes pain and fails to make the world better, then we are lower than a mosquito, because we are neglecting to fulfill the mission for which we were created. A blood-sucking, sleep depriving mosquito is just doing the job of being a mosquito, but a selfish, lazy or spiteful person is not what a person is supposed to be.
In this way, the mosquito does actually make a valuable contribution to the world. It teaches us this very lesson, that being a good mosquito is not being a good person. Unless you want to be worse than an annoying insect, you had better be contributing to the world in a positive way. A day cannot go by without doing a mitzvah. We are not on this earth to eat and party and sit around watching our life go by, we are here to create a buzz about goodness and fix the world. The mosquito is doing his buzz, you do yours.