We all have an idea about what constitutes a healthy diet: plenty of fruit and vegetables, not too much sugar, not too many saturated fats, and lots of variety. But we also do not stick to it. Many of us stuff ourselves with sweets, junk food or sugary drinks – even though we know they are bad for us. Plenty of animals also seem to eat rubbish. In fact they go far further than we do, often eating things we would regard as not just unhealthy, but positively disgusting or even dangerous. But these creatures are not eating senselessly. Their strange diets have benefits, and they suggest that there can be more to food than mere nutrition.
http://www.bbc.com/earth/story/20160721-there-are-animals-that-eat-soil-toxins-and-even-their-poo
