Which of the following is not a social insect?

Step 1: Analyze the question We need to find the insect that does NOT live in organized colonies.

Step 2: The concept Social insects live in colonies with:

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

These are called eusocial insects. Examples are termites, ants, honeybees, and some wasps.

Step 3: Check each option

• A. Termite: Lives in colonies with a queen, king, workers, and soldiers. It is social.
• B. Housefly: Lives alone. Females lay eggs on decaying matter or refuse, and there is no caste system or cooperative care of the young. It is not social.
• C. Honeybee: Lives in a hive with a queen, workers, and drones. It is social.
• D. Ant: Lives in colonies with queens, workers, and soldiers. It is social.

Step 4: Answer The housefly is the only solitary insect in the list, so the answer is B.

Tip: Remember that the social insects are the "T-A-B-W" group: Termites, Ants, Bees, Wasps. Insects that only gather around food or waste, such as houseflies, cockroaches, and mosquitoes, are not social, because gathering is not the same as organized colony life.