Because that is how they get their food.
yes
The planet can survive without light, but you won't
Some plants like mushrooms and fungi can survive without sunlight.
It becomes carnivorus
no
They can survive if they leave very inconspicuously, without making vibrations in the female spider's web.
Sun yes. Light no.
5g
they drink the pee.
They need photosynthesis to survive
Yes, all species of spiders need water to survive.
all plants and trees will die people cant survive without heat and light we cannot survive we will freeze to death
they catch small insects and fish