UPVC windows are cleaned with water and vinegar mixed in a sprayer. Jupiterimages/BananaStock/Getty Images. Unplasticized polyvinyl choloride, or UPVC, is a rigid and chemically resistant plastic used often in window and door frames.
Clutch size: 35-50 eggs. In April or May, the female crocodile will build a nest of loose dirt in a mound by the water's edge and lay her eggs. She buries the eggs and fiercely guards her nest. When the eggs hatch in July or early August, the female helps carry her young to the water.
All birds lay eggs; most lay them in nests. One of the most remarkable ploys of placing its eggs out of reach of most predators is demonstrated by the African palm-swift. It uses its own saliva to glue its nest, a little pad of feathers, to the vertical underside of a palm frond.