Footfall is also the name of a book by Larry Niven and Jerry
Pournelle. It covers "first contact", happening when an
alien species reaches earth (approximately in the
90ties of the 20th century). Some fighting erupts which
shows (and is maybe also partially caused by) the totally
different ways of acting of humans and the
aliens, which are quite detailed characterized. The
end has a "humans are the best"-touch , though.
An
interesting book showing how
strange even familar looking aliens (they vaguely resemble
elephants) can be.