There is an ongoing debate about the over-use of animals for diferent human purpouses, like food or research. Some people believe that this has been needed for the advance in society, some others argue that it is unethical. In my point view, the use of animals as part of the research programs, has allowed the discovery of medical devices, the grow of pharmaceutical industries and the rise in scientific knowledge; aditionally the incorporation of animal´s protein in human´s diet, enableled our predecessors to evolve in may aspects. However the science also demonstrared that animals have sensations and feel pain, so I strongly believe that we could find a balance to use animals in humans favor, without hurting them.