Simple categories matching solitary:

• felid,
• female,
• activity,
• process,
• animal,
• fish,
• predator,
• act,
• cat,
• bovid,
• behavior,
• undertaking,
• ape,
• occupation,
• pastime,
• profession,
• action,
• practice,
• carnivore,
• event,
• organism,
• work,
• wasp,
• recreation,
• project,
• pursuit,

Members with property solitary:

• sorting_mail,
• carpentry,
• writing,
• heron,
• reading,
• drosophila,
• emu,
• sand_wasp,
• art,
• tigers,
• painting,
• day,
• bull_elephant,
• snook,
• leopard,
• civet,
• music,
• male_gaur,
• needlework,
• mud-dauber_wasp,
• web_design,
• cheetah,
• limpet,
• gardening,
• kingfisher,
• hunting,
• solitary_play,
• florida_panther,
• aurochs,
• fasting,
• shark,
• eagle,
• casino,
• sculpture,
• feeding,
• research,
• elephant,
• exercising,
• craft,
• polecat,
• masturbation,
• building,
• shrew,
• bowling,
• orangutan,
• archery,
• felid,
• web_browsing,
• lynx,
• yard_work,
• playing,
• spider,
• baboon,
• interest,
• tiger,
• marten,
• play,
• thesis_project,
• hobby,
• rhinoceros,
• communal_animal,
• camping,
• spider_wasp,
• jaguar,
• puma,
• office_organization,
• schoolwork,
• permit,
• steinbok,
• study,
• cat,
• skiing,
• bird,
• tool_use,
• lizard,
• mongoose,
• wolf,
• cooking,
• woodworking,
• bream,
• slot-machine_game,
• ascension,
• cicada-killer_wasp,
• cougar,
• photography,
• organ-pipe_wasp,
• fishing,
• approach,
• chimpanzee,
• drawing,
• doctoral_research,
• playing_game,
• target_shooting,