Some family farmers store animal droppings in containers and capture natural gas from the droppings for fuel. what is the fuel called? methane propane ethane octane

Amale bird-of-paradise uses a dance to attract mates in which it flaps its tail feathers on the ground and jumps around a potential female mate. a different male bird-of-paradise does a similar dance but it jumps around the female in the opposite direction. the female bird is only attracted to one style of dance, in one direction. this is an example of speciation.