they are layered mounds of deposits made by precambrian algae
Answer
Photosynthesis
Explanation
The sun keeps the carbon cycle working by providing light energy. This light energy is used to carry out a process called photosynthesis by organisms that are known as producers. This process creates organic matter from carbon dioxide and water. Photosynthesis thus helps maintain the activity of carbon sinks.
The squirrels are attuned in their brains to understand that owls are a threat because it is a predator. This is visual stimuli that evolved over many years to elicit a conditioned response. This is an innate behavior (meaning that it has been pre-programmed into an animal's genes) and offspring are naturally born with it.
This question seems a teeny bit too trivial for the site but I'll bite: it could be a sign of mating or playful fighting (birds can compete for dominance, like any other animal). If the parrots are of different sexes, it is typical for them to mate if they are in the same enclosure. If they are not able to reproduce, this should cause no concern.
