Do Heat Seeking Missiles Have Teleology?

I think I have a different understanding of what teleology is. Using the heat seeking missile example, a teleological explanation for the whole missile is that it is meant to shoot down airplanes as part of a military operation. The fuel in the missile is there to hurl the missile towards a plane. The sensor in the front portion of the missile is meant to track the heat given off from an airplane’s exhaust. Teleology is defined as “the explanation of phenomena by the purpose they serve rather than by postulated causes”. I’m not clear on how this definition is being used with reference to life.