Pigeons are often seen as dirty birds and an urban nuisance, but they are just the latest in a long line of animals that have been found to have abilities to help humans.
The chimp had a sweet and tactile side but could also be violent, messy and vicious. But as Marsh points out, that's what chimpanzees are like, that's how they behave.
Some villages in the world still suffer from problems such as poor road conditions, shabby toilets, dirty environment, and undeveloped basic public services.
He started to take off his shoes, but fell to staring at the white plaster wall opposite him, broken by long streaks of dirty brown where rain had leaked through the roof.
The International Organization for Migration reports nearly 350,000 people are still living in squalid camps three years after the devastating earthquake in Haiti.
But when Charles' hidden agenda threatens to expose the government's dirty little secrets, what started out may cost Kathy her career and even her life.