Tetralogy of Fallot is a birth defect that affects normal blood flow through the heart. It happens when a babyâs heart does not form correctly as the baby grows and develops in the motherâs womb during pregnancy. It is a congenital defect, meaning the baby is born with it.Tetralogy of Fallot is made up of the following four defects of the heart and its blood vessels: 1  A hole in the wall between the two lower chambersâor ventricles âof the heart. 2  This condition also is called a ventricular septal defect.t is a congenital defect, meaning the baby is born with it. Tetralogy of Fallot is made up of the following four defects of the heart and its blood vessels: 1  A hole in the wall between the two lower chambersâor ventricles âof the heart. 2  This condition also is called a ventricular septal defect.
A drey â or dray â is a nest of a tree squirrel or a flying squirrel. Dreys are usually built of twigs, dry leaves, and grass, and typically assembled in the forks of a tall tree.They are sometimes referred to as âdrey nestsâ to distinguish them from squirrel âcavity nestsâ (also termed âdensâ).quirrels may also nest in attics or exterior walls of buildings, where a drey may be regarded as a fire hazard, as some squirrels have a habit of gnawing on electrical cables. At other times, squirrels may inhabit a permanent tree den in the hollow of a trunk or large branch.
When you look up at the trees and see nests of sticks and leaves, you may think theyâre for the birds. But think again! Did you know that squirrels also build nests? Squirrel nests are called dreys, and they are made of woven twigs and leaves, then lined with soft material, such as feathers and grass. Dreys are built high enough in the trees to keep the squirrels safe from predators, but low enough so they can withstand high winds.