It lives on low vegetation in damp areas, and feeds on flying insects which it catches in its web.

T. extensa is distinguished from other members of the genus Tetragnatha by the minute curved tip of the male's conductor (part of the pedipalp), and the form of the female's spermatheca.

In North America, it is found from Alaska to Newfoundland, and its range extends south to Washington, Colorado and Pennsylvania.

[5] The egg sacs are globular and covered with grey tufted silk,[3] resembling a bird dropping,[5] and are pressed against a plant stem.

[3] Tetragnatha extensa was first given a binomial by Carl Linnaeus in his Systema Naturae of 1758, the starting point of zoological nomenclature.