This process is characterised as an infradian rhythm since it is a biological cycle with a period longer than 24 hours, and in arthropods, this process is called ecdysis. For 10 points each:
[10m] Name this process, achieved in some squamates by rubbing their heads against hard objects. In mammals this process is triggered in summer by light levels rather than temperature.
ANSWER: moulting [or descriptive answers such as shedding skin, sloughing off and so on]
[10e] This mood disorder is categorised as infradian as it occurs during winter, when hours of sunlight are reduced. It is typically treated with light therapy or SSRIs.
ANSWER: Seasonal Affective Disorder [or SAD; prompt on seasonal or winter depression]
[10h] One manifestation of infradian rhythms is this condition, which occurs during the luteal phase of the menstrual cycle and affects 3-8% of people who menstruate. Its symptoms can include severe mood swings and anxiety, difficulty sleeping, and low energy.
ANSWER: premenstrual dysphoric disorder [or PMDD; prompt on premenstrual syndrome or PMS]