noxious - injurious to physical or mental health; noxious chemical wastes; noxious ideas. harmful - causing or capable of causing harm; too much sun is harmful to the skin; harmful effects of smoking.
Newborn kittens, also sleep more -- upwards of 16 hours a day. Although newborns sleep a lot, it generally isn't continuous. Newborn kittens take frequent naps which often last for mere minutes at a time. Young cats usually develop their sleeping behaviors once they're around three months in age.
On average, dogs sleep about 14 hours a day (though large breeds may sleep more), while cats spend 15 to 20 hours snoozing (yes, be jealous). Dogs tend to nap during the day and sleep through the night, while cats get most of their shuteye during daytime hours and are most active after dark.