Caterpillar in the context of "Apocrita"

A larva (/ˈlɑːrvə/; pl.: larvae /ˈlɑːrviː/) is a distinct juvenile form many animals undergo before metamorphosis into their next life stage. Animals with indirect development such as insects, some arachnids, amphibians, or cnidarians typically have a larval phase of their life cycle.

A larva's appearance is generally very different from the adult form (e.g. caterpillars and butterflies) including different unique structures and organs that do not occur in the adult form. Their diet may also be considerably different. In the case of smaller primitive arachnids, the larval stage differs by having three instead of four pairs of legs.

Ambiguity is the type of meaning in which a phrase, statement, or resolution is not explicitly defined, making for several interpretations; others describe it as a concept or statement that has no real reference. A common aspect of ambiguity is uncertainty. It is thus an attribute of any idea or statement whose intended meaning cannot be definitively resolved, according to a rule or process with a finite number of steps. The prefix ambi- reflects the idea of "two", as in "two meanings".

The concept of ambiguity is generally contrasted with vagueness. In ambiguity, specific and distinct interpretations are permitted (although some may not be immediately obvious), whereas with vague information it is difficult to form any interpretation at the desired level of specificity.

An oak is a hardwood tree or shrub in the genus Quercus of the beech family. They have spirally arranged leaves, often with lobed edges, and a nut called an acorn, borne within a cup. The genus is widely distributed in the Northern Hemisphere, with some 500 species, both deciduous and evergreen. Fossil oaks date back to the Middle Eocene. Molecular phylogeny shows that the genus is divided into Old World and New World clades, but many oak species hybridise freely, making the genus's history difficult to resolve.

Ecologically, oaks are keystone species in habitats from Mediterranean semi-desert to subtropical rainforest. They live in association with many kinds of fungi including truffles. Oaks support more than 950 species of caterpillar, many kinds of gall wasp which form distinctive galls (roundish woody lumps such as the oak apple), and a large number of pests and diseases. Oak leaves and acorns contain enough tannin to be toxic to cattle, but pigs are able to digest them safely. Oak timber is strong and hard, and has found many uses in construction and furniture-making. The bark was traditionally used for tanning leather. Wine barrels are made of oak; these are used for aging alcoholic beverages such as sherry and whisky, giving them a range of flavours, colours, and aromas. The spongy bark of the cork oak is used to make traditional wine bottle corks. Almost a third of oak species are threatened with extinction due to climate change, invasive pests, and habitat loss.

Countershading, or Thayer's law, is a method of camouflage in which an animal's coloration is darker on the top or upper side and lighter on the underside of the body. This pattern is found in many species of mammals, reptiles, birds, fish, and insects, both in predators and in prey.

When light falls from above on a uniformly coloured three-dimensional object such as a sphere, it makes the upper side appear lighter and the underside darker, grading from one to the other. This pattern of light and shade makes the object appear solid, and therefore easier to detect. The classical form of countershading, discovered in 1909 by the artist Abbott Handerson Thayer, works by counterbalancing the effects of self-shadowing, again typically with grading from dark to light. In theory this could be useful for military camouflage, but in practice it has rarely been applied, despite the best efforts of Thayer and, later, in the Second World War, of the zoologist Hugh Cott.

Butterflies are winged insects from the lepidopteran superfamily Papilionoidea, characterised by large, often brightly coloured wings that often fold together when at rest, and a conspicuous, fluttering flight. The oldest butterfly fossils have been dated to the Paleocene, about 56 million years ago, though molecular evidence suggests that they likely originated in the Cretaceous.

Butterflies have a four-stage life cycle, and like other holometabolous insects they undergo complete metamorphosis. Winged adults lay eggs on plant foliage on which their larvae, known as caterpillars, will feed. The caterpillars grow, sometimes very rapidly, and when fully developed, pupate in a chrysalis. When metamorphosis is complete, the pupal skin splits, the adult insect climbs out, expands its wings to dry, and flies off.

The house sparrow (Passer domesticus) is a bird of the sparrow family Passeridae, found in most parts of the world. It is a small bird that has a typical length of 16 cm (6.3 in) and a mass of 24–39.5 g (0.85–1.39 oz). Females and young birds are coloured pale brown and grey, and males have brighter black, white, and brown markings. One of about 25 species in the genus Passer, the house sparrow is native to most of Europe, the Mediterranean Basin, and a large part of Asia. Its intentional or accidental introductions to many regions, including parts of Australasia, Africa, and the Americas, make it the most widely distributed wild bird.

The house sparrow is strongly associated with human habitation, and can live in urban or rural settings. Though found in widely varied habitats and climates, it typically avoids extensive woodlands, grasslands, polar regions, and hot, dry deserts far away from human development. For sustenance, the house sparrow routinely feeds at home and public bird feeding stations, but naturally feeds on the seeds of grains, flowering plants and weeds. However, it is an opportunistic, omnivorous eater, and commonly catches invertebrates such as insects and their larvae, caterpillars, and many other natural foods.