Magic Dust is a rare resource used to upgrade habitats. You need to upgrade habitats to increase your maximum Energy capacity so you can get the most out of adventures.
Each habitat can only be upgraded once. To be upgraded, a habitat must have at least two animals settled. Be careful - if you move an upgraded habitat or one of the animals in that habitat to the warehouse, you will lose the upgrade.
You can get Magic Dust as a reward for completing adventure quests or buy it in adventure shops. You might also find some Magic Dust after removing an obstacle in an adventure.