Enderman Doesn't Chase Endermite And Endermite Spins

I expected the Enderman to chase the Endermite out of my building, like they usually do. What happened was the Enderman did nothing, the Endermite crawled up to it and then started spinning.

Steps to recreate:
1. Spawn an Enderman.
2. Spawn an Endermite.
3. Watch the Enderman and Endermite.