Three of them are doing just fine. However, one of them has a problem as evidenced by the leaves which look as if someone has held a candle too close to the edges of each leaf and they have become brown and crispy - covering almost half of the leaf, but starting with the outside edge (away from the stem).
Again infants and children normally drool during sleep, but some adults too drool during sleep. Moreover, drooling in case of adult is not always normal. Drooling can be quite common in adult while sleeping. But when awake, drooling in adult can not only be embarrassing but very uncomfortable leading to social and mental burden. The reasons for an adult to drool during sleep can be due to an open mouth, abnormal structure of the mouth like enlarged tonsils, large tongue or overcrowded teeth.
Drooling is common in cats and may be caused by many different conditions. The medical term for excessive production of saliva is 'pytalism.' Drooling may also be called 'hypersalivation.'. What causes drooling in cats? Drooling may be caused by an overproduction of saliva or a reluctance or inability to swallow. Drooling in cats may be associated with the following: 1  Dental disease such as gingivitis, stomatiis, or periodontal disease.  Other diseases of the mouth such as oral ulcers, cancer, or a foreign body in the mouth.