Which of the following pairs are social insects?

Analyze the question: You're asked to pick the pair in which both insects are social insects.

Explain the concept: Social insects live in organized colonies with:

• A division of labour (workers, soldiers, reproductives/queen)
• Cooperative care of the young
• Overlapping generations living together

This is called polymorphism or caste system. Typical examples are termites, ants, bees, and wasps.

Step-by-step solution:

• A. Termite and locust: Termites are social, but locusts are not. They swarm, but they have no castes or division of labour. ✗
• B. Ants and cockroach: Ants are social, but cockroaches are not. They merely aggregate. ✗
• C. Cockroach and bee: Bees are social, but cockroaches are not. ✗
• D. Termite and bee: Termites have a queen, king, workers, and soldiers. Bees have a queen, drones, and workers. Both are social. ✓

Note: Option B contains one true social insect (ants), but the pair fails because of cockroach. Only option D has two social insects.

Answer: D. Termite and bee

Exam tip: Remember the social insects with the mnemonic "TABW": Termites, Ants, Bees, Wasps. If an option contains a locust or cockroach, eliminate it right away. Both are solitary or non-social insects.