A human being, a beaver and an ant have a lot in common. Few animals, as part of their daily existence, consciously seek to alter the environment. Think about the typical cow. It spends much of its time eating.
It will eat whether it is in the company of other cows in the field or alone locked up in a single pen. In between bites of food it snoozes and grows older.
If annoyed it may break something but you will never go away and come back to find a cow has built a little shade for it to lie in because it is February and especially hot. Not so the beaver.
There are two related species, found in North America and Europe respectively. Born engineers they have a trait of building dams on rivers to create an area of still deep water that protects them against predators.
They get the raw material they need by cutting down trees and other plants using their powerful front teeth. Within the dam, the homes they build for themselves are called 'lodges'. Living in Kenya, we are unlikely to meet beavers so we will not talk about them anymore.
A more familiar species to us are ants. There exists thousands of species and they have colonised every part of the planet except Antarctica and possibly the North Pole.
Everywhere you step there is a high chance that there is an ant within centimetres. You recognise an ant because of the distinctive waist it has together with the antennae on its head.
They share some characteristics with wasps and are distantly related. Ants live in colonies, which range in size from small 100 ant communities to those with millions of ants.
Similar in fact to the way human beings live, from small isolated groups of families to large cities. The success of ants in being able to adapt to different environments has been attributed to their social organisation and importantly their ability to modify those habitats, tap resources, and defend themselves. In other words ants play good politics.
As human beings we say that ants do not think, and that everything they do is based on instinct. However one thing that they do well is take care of their living environment.
For humans, the branch of public health that deals with all aspects of natural and built environment that affects human health is called environmental health.
A slightly different way of thinking about the same thing is to look at how health and disease are determined by factors in the environment.
So environmental health is the study of those factors and devising interventions that influence those factors to improve human health. The goal is to have an environment that supports good health.
One basic universal right we all have is to decent and adequate housing. A house has several definitions ranging from the structure itself to what is culturally appropriate for particular people.
All the definitions have an impact on health. Looking at just the structure used to build a house is important. In parts of North Eastern Kenya, people build houses using polythene sheets tightly bound on to a basic frame made of flexible sticks. One of the reasons they have adopted this material is that they wish to protect themselves against strong winds and fine sand dust.
The atmosphere inside the hut is therefore one of still air in comparison to the outside. The structures are not very big, really in effect a tent where people retire to sleep at night.
One health effect is that health-wise there is crowding. Combine these factors and you have good breeding ground for the spread of tuberculosis.
A different approach is to build a stone house, complete with ceiling boards. Do this in western Kenya next to extensive bush and live in that house for 10 to 20 days a year and chances are high that all you have done is built a nice house for bats to come and live in.
They will love the walled off space created by the ceiling. After a few years, the bat droppings smell and dust will begin to seep through into the rooms below.
Culture dictates that people of a certain age need to build a house even though they hardly live in them. Practically after a 'holiday' you return broke, having spent a week or so inhaling bat waste dust. Healthy? Not really.
Almost everything we do has a health impact and the way we conduct our politics has the largest impact. We should be looking for leaders who help improve our health, not just by promising to build hospitals, that is needed but shallow thinking, but by looking at the factors that determine our health before we need healthcare.