A recent study found both humans and domestic dogs receive a dramatic increase of oxytocin, the bonding hormone, from the other when staring into each other’s eyes. – WTF Fun Facts
Source: https://www.sciencemag.org/news/2015/04/how-dogs-stole-our-hearts
hormone
natural alarm clock wake up anytime you want
Natural alarm clock, wake up anytime you want – WTF fun facts