Just opened my plastic shoe box which houses my small bunch of mealworms, only to find lots and LOTS of beetles. I'm so thrilled I didn't kill 'em all !!! So fun to see the different stages - I wondered if I would have enough beetles for breeding, as my starter mealworms were from a bait store - probably started with a couple dozen worms. Any ideas on how to determine beetle gender, or is that too personal a question to ask the little beetles ??? 
