---- Pls ignore - I thought it was about TS4 :) ----
Do you have City Living? I sometimes will find a sim with lots of related items, like the entire collection. I think the sim has been tending a NPC sales table during a festival or at a market place. The game fills its inventory with say crystals r frogs, and the sim will restock the sales table. Whatever was not sold will be kept in the inventory. I assume the game will on ly assign such a task to unemployed sims, so to avoid it you could just sign up with the "work office" to add a work title, or get a real job. Your problem might come from story progression mod though, as I never saw them selling insects...
