There is major problem of pigeons in many areas now a days. They get easy access from open window balcony, plumbing ducts & find good nesting area on the pipes & parapets inside the duct. They make nests & lay eggs there. There is a big problem of bird droppings inside the ducts which can not be easily cleaned & emits a very foul smell. Many pigeons die in the ducts causing large presence of maggots & other insects in the duct area.