Locating Structures
Alien structures spawn naturally throughout your world, but they're not common. You'll need to explore multiple biomes to find one. Structures can appear in jungles, savannas, deserts, and other terrain types. Look for large, unusual buildings that don't match vanilla Minecraft architecture—they often have distinctive shapes and are made from blocks you won't recognize.
Search Strategy
Start by traveling far from your spawn point. Structures generate more reliably when you move into unexplored chunks. Use a horse or boat to cover ground quickly. Watch the horizon for large silhouettes that stand out from the landscape.
If you're having trouble, try visiting different biome types. The mod spreads structures across various environments, so a jungle, savanna, or mesa biome is worth checking. Once you find one structure, others are usually not too far away.
Inside the Structure
When you enter, look for the alien DNA item—either 
Appoplexian fur or 
Polymorph goo. These items are typically placed in accessible locations within the building. Grab the DNA and return to safety to transform.
