My favorite natural law is the Law of Unintended Consequences.
Here is a good example. The leopard is one of the most elusive and feared predators in the world. The last thing you would want is a big 
cat like this in a populated area.
Or would you? There is a recent study in the journal Frontiers in Ecology and the Environment with the unlikely title of “Leopards provide public health benefits in Mumbai, India” (https://esajournals.onlinelibrary.wiley.com/doi/abs/10.1002/fee.1776). You see, India has a large number of feral dogs — estimates range as high as 30 million. The health angle is many of these dogs are infected with rabies; about 20,000 people per year in India die of this dreaded disease, most of them from dog bites. A leopard in the neighborhood will control the dog population and thus save people from getting bitten by a dog.
Unfortunately, it’s not all win-win. Wild leopards can’t be controlled and people are occasionally attacked. The problem is people tend to focus only on the negative; this study shows there is a positive side that is well worth considering. If you live in an Indian slum, a leopard may be a big part of health policy.
For more information, see “Urban Leopards Can Save Lives By Eating Feral Dogs” by Matthew L. Miller (https://blog.nature.org/science/2018/03/08/urban-leopards-can-save-lives-by-eating-feral-dogs/? ). The photo came from that site.