variety of flying birds silhouettes over white background

>For other uses, see Bird (disambiguation). Many - see section below. Birds are bipedal, warm-blooded, egg-laying vertebrates characterized primarily by feathers, forelimbs modified as wings, and hollow bones. Birds range in size from the tiny hummingbirds to the huge Ostrich and Emu. Depending on taxonomic viewpoint, there are about 8,800–10,200 living bird species (plus about 120–130 that have become extinct in the span of human history) in the world, making them the most diverse class of terrestrial vertebrates. See more at Wikipedia.org...

>This article is about the insect. For other meanings, see Fly (disambiguation) As defined by entomologists, a fly (plural flies) is any species of insect of the order Diptera, some of which can land on food and transmit bacteria to humans. A few, like Ormia ochracea, have very advanced hearing organs. Flies are common amongst humans and have caused many diseases to spread in the past. The house-fly (Musca domestica) and mosquito are particularly common amongst humans. Other flies, such as the horse-fly (Family Tabanidae), can inflict painful bites. The larva of a fly is commonly called a maggot. See more at Wikipedia.org...

houette is a view of an object or scene consisting of the outline and a featureless interior. The term comes from Étienne de Silhouette, Louis XV's miserly finance minister. See more at Wikipedia.org...