The answer is competition. It's competition because they are protecting their territory, so their way of protecting or fighting for their territory is to urinate on their territory. By a way of showing that they don't want nobody in their territory.
I actually did the math for this a while ago. In order to install solar panels to every house in America it would cost a one time payment of about 900 billion dollars. We spend 700 billion on fossil fuels each year so in two years it would already pay itself off them we'd actually profit from it. Even if you don't believe in global warming you can't argue with that.
I think the answer is chemical change
The change in internal energy of the combustion of biphenyl in Kj is calculated as follows
=heat capacity of bomb calorimeter x delta T where delta T is change in temperature
delta T = 29.4 -25.8= 3.6 c
= 5.86 kj/c x 3.6 c = 21.096 kj