sentences:  Over a lifetime they can cover millions of kilometers.Feeding parties can be very large in insect-rich areas, such as wetlands.Reports of as many as 2000 swifts feeding over flooded gravel pits, lakes and marshy river deltas are not uncommon, and may represent an ingress of swifts from within as much as a radius; swifts nesting in Western Scotland are thought to venture to Lough Neagh in Northern Ireland to feed on the abundant and nutritious "Lough Neagh Fly".