Adult wasp hatching. Surface of the nest of the wasp Polistes sp., showing an adult hatching. A row of cells of the nest is seen. At centre, a newly formed adult has bitten its way through the lid of a cell, and its antennae and yellow and black head are emerging. The queen of the nest builds these hexagonal cells from chewed- up dry plant material mixed with saliva. After laying her eggs she feeds the hatched larvae on meat; fully formed larvae close each cell and spin a silk cocoon. Four to six weeks after the egg is laid the larva pupates to produce this infertile adult female worker.