The Amazon rainforest spans Brazil, Peru and other countries, and formed over 55 million years ago. It contains over 90,000 tons of plants per square meter and is home to 2.5 million insect species, tens of thousands of plant species, and over 2,000 bird and mammal species. Common animals include the spider monkey, jaguar, anaconda and giant river otter. The rainforest is threatened by deforestation for farming which damages habitats and ecosystems.