Because they have more underlying factors such as (straight) brown hair or (curly) blonde hair from different parents. A punnet square would be too big and confusing if we considered all the factors that came from the parents.
Yes it would blow heat around the house ....................
Physical is something you can have/ hold and mental is something in ur head that you can't see or hold.
They produce narrow-band high-frequency sound to help them navigate in water. These high-frequency sounds are used in echolocation. Echolocation is used to identify and locate prey and also avoid the predators. Marine mammals like whales and dolphin use echolocation in different manners.