We discovered that spiders use seed heads of Sarracenia purpurea (Northern Pitcher Plant) for moulting, nesting, and rearing of young. These associations represent only a few of the diverse interactions between spiders and pitcher plants. During July–August 2001 at Acadia National Park, seed heads (n = 301) of S. purpurea from four bog-heaths yielded spiders (n = 685) of four families (Theridiidae, Dictynidae, Clubionidae, Salticidae), 10 genera, and at least 11 species. Two additional spider families (Gnaphosidae, Thomisidae) were represented by cast exuviae. Jumping spiders (Salticidae) were the chief occupants, comprising 80.0% of species and 99.1% of individuals. The salticid Tutelina similis was the most common inhabitant, accounting for 63.8% of the overall spider fauna in these microhabitats. Spider foraging-guild presence favored hunters (99.7%) over web spinners; juveniles outnumbered adults almost 15 to 1, and females outnumbered males 43 to 1. Frequencies of spider webbing and retreats in seed heads were greater than expected (G-test, α = 0.05); however, spider occupancy was less than expected. Seed heads with multiple-spider occupants were more frequent than those with single-spider occupants; conspecific associations were more frequent than heterospecific associations. No evidence was found that spiders preferred either closed or open seed heads. Other associated arthropods included parasitic mites, spider-egg parasitoids, and insects. The identified taxa represent the first records of spiders inhabiting seed heads of S. purpurea in Maine.