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.
Many nests are still flooded every year, however, killing all the unhatched embryos - in saltwater crocodiles flooding is the main cause of embryo mortality, not destruction by predators. If the nest is in danger of getting too dry, the female has apparently been observed to splash water onto it from a purpose-dug, adjacent pool, although the veracity of this observation is unknown.