Tetragnathid spider posing as thorns ignores a nosy ant

Arachnida (Arachnids) / Araneae (Spiders) /  Family: Tetragnathidae (Longjawed Orb Weavers) / Tetragnatha
Also commonly known as large-jawed orb weavers, Tetragnathid orb weavers
Live adult spiders photographed Winfield, IL .    41°53'04" N     88°09'36" W  elevation 715 ft. 

Tetragnathid spiders are fairly easy to identify by their huge, powerful jaws, or chelicerae, and long, slender abdomen. Like the other family of orb weavers, the Araneidae, these spiders have eight eyes and 3 claws on each tarsus. There are about 25 species in North America. The Venusta Orchard spider, a very common woodland arachnid, is a member of this family. Its abdomen is not nearly as slender as the spiders pictured here.

Habitat: Meadows and marshes, woodland edges. Food: insects. Most members of this family do not build vertical webs, they are usually tilted and sometimes close to horizontal. In some species, only the spiderlings produce webs. The orchard spiders build their webs in shrubs or trees. Here is Long-jawed orb weaver on Wikipedia.