Get smart curated videos delivered to your inbox.   SUBSCRIBE
The Kid Should See This

How do cliff swallows build their mud pellet nests?

Watch more with these video collections:

From the Cornell Lab of Ornithology, watch as some cliff swallows gather small chunks of mud from the water’s edge, and then, against a cliffside or man-made wall, stack the mud pellets around themselves like 1,000 drippy bricks. The sand, silt, and clay mud that they choose keeps the nest from crumbling as it dries. The birds might also line the inside of the nest with grass and feathers.

In nesting colonies of up to 3,700 nests, Cliff Swallows can be found in North America during the spring and summer. From

One easy way to find Cliff Swallows is to look for their gourd-shaped mud nests clustered under horizontal overhangs—many a highway overpass is swarming with Cliff Swallows in summer. To find these birds while they’re out foraging, head to a lake, river, or wetland and seek out foraging flocks of swallows. Scan the swallows carefully, focusing on finding a square-tailed bird with a pale, pumpkin-colored rump and dark upperparts. Scan the upper levels of a foraging flock, as Cliff Swallows often forage higher than other species.

mud pellet nests
Listen to their calls at, or

Related watching: more videos with nests, including the Weaver Birds intricate nests and the Burrowing Owl’s Cozy Underground Home.

This Webby award-winning video collection exists to help teachers, librarians, and families spark kid wonder and curiosity. TKSST features smarter, more meaningful content than what's usually served up by YouTube's algorithms, and amplifies the creators who make that content.

Curated, kid-friendly, independently-published. Support this mission by becoming a sustaining member today.