Instead of migrating in response to cold weather, some organisms have the ability to enter a state of deep sleep. The animal's body temperature drop and activities slow down to conserve energy. This process is known as - * immigration
coma
winter slumber
hibernation

According to ohrp, a problem is an “unanticipated problem” when it meets which of the following criteria: unexpected, related or possibly related to the research, suggests that the research does not put the subjects or others at greater riskunexpected, related or possible related to the research, suggests the research puts subjects or others at greater riskunexpected, unrelated to the research but still occurring with a subject, suggests the research puts others at greater riskexpected, related or possible related to the research, suggests the research puts others at greater risk