Odd-one-out among flying-related entities: Bird, Insect, Aeroplane, Kite. Use the criterion of self-propelled capability versus dependence on an external agent to isolate the outlier.

Introduction / Context:
At first glance, all four items are associated with flight. However, odd-one-out questions usually hinge on a sharper operational property shared by three items but not by the fourth. A reliable discriminator here is whether the object can initiate and sustain flight by its own power or whether it depends on an external agent.

Given Data / Assumptions:

• Bird: a living organism that flies by flapping wings under muscular power.
• Insect: a living organism that flies via self-powered wing beats.
• Aeroplane: a vehicle that achieves sustained, controlled flight using an onboard power source and aerodynamic lift.
• Kite: a tethered, unpowered object that flies only with wind and the controller's manipulation; it cannot self-propel.

Concept / Approach:
Group by self-propulsion. Birds and insects are biologically self-powered fliers. Aeroplanes, though not living, are nevertheless self-propelled through engines. A kite differs qualitatively: it has no onboard power and cannot take off or remain airborne without wind and a person managing the line. Therefore, three items share the property of being able to generate and maintain flight under their own power, while one item requires external energy and tether control.

Step-by-Step Solution:
1) Identify the operational property: self-powered flight capability.2) Classify each item: Bird (yes), Insect (yes), Aeroplane (yes), Kite (no).3) Select the single item that lacks the shared property.

Verification / Alternative check:
Other possible criteria such as “living vs non-living” split the set 2–2 and do not yield a unique outlier. The self-propulsion criterion yields a 3–1 split and is therefore decisive.

Why Other Options Are Wrong:
Bird, Insect, and Aeroplane can all initiate or sustain flight without being pulled by a line and without relying solely on ambient wind.

Common Pitfalls:
Choosing Aeroplane as the outlier for being man-made. While true, that criterion does not isolate a single item because Kite is also man-made; hence it does not produce the required 3–1 grouping.

Final Answer:
Kite