system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Are we the only species to get headaches if so why?
gpt
No, many species are physiologically similar to people. The same imbalances that cause headaches in humans cause them in other species. 

Brain tumors give bears headaches. 

Rats can get hangover headaches. 

Cats have been disfigured by selective breeding and have sinus headaches.