Pressure is a type of Sensation. Hunger is a type of Sensation. Food can be used for Hunger. 
Behavior is related to Play. Play is a type of Compete. Compete requires Improve. 
Pressure --IsA--> Sensation <--IsA-- Hunger <--UsedFor-- Food 
Behavior <--RelatedTo--> Play --IsA--> Compete --HasPrerequisite--> Improve 