Egg (biology) in the context of "Eggshell"

A nest is a structure built by certain animals to hold their eggs or young. Although nests are most closely associated with birds, members of all classes of vertebrates and some invertebrates construct nests. They may be composed of organic material such as twigs, grass, and leaves, or may be a simple depression in the ground, or a hole in a rock, tree, or building. Human-made materials, such as string, plastic, cloth, or paper, may also be used. Nests can be found in all types of habitat.

Nest building is driven by a biological urge known as the nesting instinct in birds and mammals. Generally each species has a distinctive style of nest. Nest complexity is roughly correlated with the level of parental care by adults. Nest building is considered a key adaptive advantage among birds, and they exhibit the most variation in their nests ranging from simple holes in the ground to elaborate communal nests hosting hundreds of individuals. Nests of prairie dogs and several social insects can host millions of individuals.

Insecticides are pesticides used to kill insects. They include ovicides and larvicides used against insect eggs and larvae, respectively. The major use of insecticides is in agriculture, but they are also used in home and garden settings, industrial buildings, for vector control, and control of insect parasites of animals and humans.

Acaricides, which kill mites and ticks, are not strictly insecticides, but are usually classified together with insecticides. Some insecticides (including common bug sprays) are effective against other non-insect arthropods as well, such as scorpions, spiders, etc. Insecticides are distinct from insect repellents, which repel but do not kill.

An ant colony is a population of ants, typically from a single species, capable of maintaining their complete lifecycle. Ant colonies are eusocial, communal, and efficiently organized and are very much like those found in other social Hymenoptera, though the various groups of these developed sociality independently through convergent evolution. The typical colony consists of one or more egg-laying queens, numerous sterile females (workers, soldiers) and, seasonally, many winged sexual males and females. In order to establish new colonies, ants undertake flights that occur at species-characteristic times of the day. Swarms of the winged sexuals (known as alates) depart the nest in search of other nests. The males die shortly thereafter, along with most of the females. A small percentage of the females survive to initiate new nests.

Breeding pair is a pair of animals which cooperate over time to produce offspring with some form of a bond between the individuals. For example, many birds mate for a breeding season or sometimes for life. They may share some or all of the tasks involved: for example, a breeding pair of birds may split building a nest, incubating the eggs and feeding and protecting the young. The term is not generally used when a male has a harem of females, such as with mountain gorillas.

True breeding pairs are usually found only in vertebrates, but there are notable exceptions, such as the Lord Howe Island stick insect. True breeding pairs are rare in amphibians or reptiles, although the Australian Shingleback is one exception with long-term pair-bonds. Some fish form short term pairs and the French angelfish is thought to pair-bond over a long term. True breeding pairs are quite common in birds. Breeding pair arrangements are rare in mammals, where the prevailing patterns are either that the male and female only meet for copulation (e.g. brown bear) or that dominant males have a harem of females (e.g. walrus).

Holometabolism, also called complete metamorphosis, is a form of insect development which includes four life stages: egg, larva, pupa, and imago (or adult). Holometabolism is a synapomorphic trait of all insects in the clade Holometabola. Immature stages of holometabolous insects are very different from the mature stage. In some species, a holometabolous life cycle minimizes competition between larvae and adults by separating their ecological niches. The morphology and behavior of each stage are adapted for different activities. For example, larval traits maximize feeding, growth, and development, while adult traits enable dispersal, mating, and egg laying. Some species of holometabolous insects protect and feed their offspring. Other insect developmental strategies include ametabolism and hemimetabolism.

A clutch of eggs is the group of eggs produced by birds, amphibians, or reptiles, often at a single time, particularly those laid in a nest.

In birds, destruction of a clutch by predators (or removal by humans, for example the California condor breeding program) results in double-clutching. The technique is used to double the production of a species' eggs, in the California condor case, specifically to increase population size.

Apocrita is a suborder of insects in the order Hymenoptera. It includes wasps, bees, and ants, and consists of many families. It contains the most advanced hymenopterans and is distinguished from Symphyta by the narrow "waist" (petiole) formed between the first two segments of the actual abdomen; the first abdominal segment is fused to the thorax, and is called the propodeum. Therefore, it is general practice, when discussing the body of an apocritan in a technical sense, to refer to the mesosoma and metasoma (or gaster) rather than the "thorax" and "abdomen", respectively. The evolution of a constricted waist was an important adaption for the parasitoid lifestyle of the ancestral apocritan, allowing more maneuverability of the female's ovipositor. The ovipositor either extends freely or is retracted, and may be developed into a stinger for both defense and paralyzing prey. Larvae are legless and blind, and either feed inside a host (plant or animal) or in a nest cell provisioned by their mothers.

Apocrita has historically been split into two groups, Parasitica and Aculeata. Aculeata is a clade whose name is in standard use. "Parasitica" is not a clade, as it is paraphyletic: the clade would contain the Aculeata. "Parasitica" is therefore a rankless grouping in many present classifications, if it appears at all.Parasitica comprises the majority of hymenopteran insects, its members living as parasitoids. Most species are small, with the ovipositor adapted for piercing. In some hosts, the parasitoids induce metamorphosis prematurely, and in others it is prolonged. There are even species that are hyperparasites, or parasitoids on other parasitoids. The Parasitica lay their eggs inside or on another insect (egg, larva or pupa) and their larvae grow and develop within or on that host. The host is nearly always killed. Many parasitic hymenopterans are used as biological control agents to control pests, such as caterpillars, true bugs and hoppers, flies, and weevils.

The ovipositor is a tube-like organ used by some animals, especially insects, for the laying of eggs. In insects, an ovipositor consists of a maximum of three pairs of appendages. The details and morphology of the ovipositor vary, but typically its form is adapted to functions such as preparing a place for the egg, transmitting the egg, and then placing it properly. For most insects, the organ is used merely to attach the egg to some surface, but for many parasitic species (primarily in wasps and other Hymenoptera), it is a piercing organ as well.

Some ovipositors only retract partly when not in use, and the basal part that sticks out is known as the scape, or more specifically oviscape, the word scape deriving from the Latin word scāpus, meaning "stalk" or "shaft".