Hi there, I noticed everytime I meet an Ogre Lair, the area around it was FILLED with 3 essence squares, so I thought something was fishy, then I saw an ogre and decided to attack, 2 squares next to the ogre was 3 grain and 3 material, and as I killed the ogre and walked into its square, they both gained 3 essence.
Sadly I forgot to take a screenshot BEFORE attacking.

Sincerely
~ Kongdej