They are a species, the definition is:
A group of organisms that have similar characteristics and can interbreed to produce fertile offspring
A. The mutation that occurs during meiosis is a sure way of gene splitting I presume:)
I can't answer 1 but 2=First, make sure you weather proof the house, than go from there and try anything you think is necessary in this situation.
It’s called a solar system because solar means “relating to or determined by the sun” and system means “a set of things working together as parts of a mechanism or an interconnecting network” and the solar system is a whole bunch of planets and other things that are related to the sun and working together.