What is a good explanation of insomnia for kids?

Insomnia is when someone has trouble falling asleep or staying asleep, even when they really want to. It can make them feel tired and grumpy during the day because their bodies didn't get enough rest. Sometimes, worries, noise, or even too much screen time can make it hard to sleep. It's important to have a calm bedtime routine to help our bodies know it's time to rest.