Still other dogs begin the behaviour out of boredom, or because of underlying stress. (moderndogmagazine.com)
Look for underlying stresses that might be making you feel more irritated than usual. (marriage.com)
Amygdala transcriptome hints at cellular mechanisms underlying stress - enhanced fear learning, a rat model of posttraumatic stress disorder Igor Ponomarev, Waggoner Center for Alcohol and Addiction Research, Univ of Texas at Austin, USA (ibangs.org)