Dr. Robert Hamilton is a paediatrician in California and he has dealt with a lot of screaming babies over the years.
 
In order to comfort the poor things, he’s developed a trick to stop them from crying. He says it works every time.
 
Pick up the baby and then fold their arms across their chest. Grab the diaper area and then rock them at a 45 degree angle.
 
If it’s regular fussy-ness this will work every time. If they still cry, they are probably hungry or ill.