We've got more in common with wolves than maybe we'd like to admit - as is the case with the annoying hiccups. Probably the most adorable hiccuping I've ever seen, this video was posted by the NY Wolf Conservation Center:
Hiccups are involuntary contractions of the diaphragm - the sheet of internal skeletal muscle that extends across the bottom of the rib cage. The diaphragm separates the thoracic cavity from the abdominal cavity and performs an important function in respiration: as the diaphragm contracts, the volume of the thoracic cavity increases and air is drawn into the lungs. When you hiccup, the reflex is associated with a closure of the vocal cords, which results in the classic "hic" sound. Other mammals also have diaphragm and get the hiccups, as you can see above.
