How can I keep mealworms alive and healthy for an extended period of time?

To keep mealworms alive and healthy for an extended period of time, provide them with a suitable habitat such as a plastic container with ventilation holes, a substrate like oats or bran for them to burrow in, and a food source like fruits and vegetables. Keep the container in a dark, dry, and warm environment, and regularly clean out any waste or uneaten food to prevent mold and bacteria growth. Additionally, provide a water source like a small dish of water or fresh fruits and vegetables to keep them hydrated.