That's an unusual way of stating the question. However, human eyes have receptors that are triggered by light waves in a specific range. Ultra violet and inferred are outside that range.
because the feather is light and humans are not light
They can. While human eyes can not "see" infrared light, humans can detect this light as "heat" on the surface of the skin.
because cat's urine glows under a black light!
no insects lay eggs they cant get brith
No they cant as they do not have a voice box.
Yes they to insects but they pose no danger to humans at all even if they managed to give you abite it would not be painfull or harmfull. There is a myth that they are deadly but that they cant bite you this is not true.
if there is no plants humans cant get oxygen so naturally people cant exist on earth
No! That would be really creepy. Humans cant have dogs, and dogs cant have humans.
sorry cant answer Insects do
because they cant its there habitat their swimming is like our walking on earth they cant survive whithout water and we cant survive without gravity literally
IT CANT
Humans can exist in space for short periods of time, but they require special equipment like spacesuits and spacecraft that provide oxygen, temperature regulation, and protection from radiation. Extended stays in space can have negative effects on the human body, such as muscle atrophy and bone density loss, so it is important to take precautions and conduct thorough research on the effects of long-term space habitation.