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.
book showing how strange
even familar looking aliens (they vaguely resemble elephants
) can be.