Seasonal changes impel a wide variety of creatures, from whooper swans to monarch butterflies, to begin their epic migrations to ancient feeding, mating, and breeding grounds, sometimes covering thousands of miles and employing ingenious methods to reach their destinations. This film premiered October 18, 2009.
expiredpublic47681300472956cove4768 Full Episodeunavailabledisabledshowfalse12153Animal Homes: Cities Animals congregate in huge colonies partly out of necessity and partly for the security. 2015-04-22 00:00:00http://www.pbs.org/wnet/nature/files/2015/03/animal_homes_hour3_teaste_COVE-e1429906185866-480x270.jpg2365472551cove12076Social Spiders Build Massive Nests A spider found in the Caribbean and South America build nests more than 20 feet across. 2015-04-22 00:00:00http://www.pbs.org/wnet/nature/files/2015/04/Sequence-01.00_05_28_11.Still013-480x270.jpg2365464830cove