Keeping an audience’s attention is the top goal of every speaker. Be relevant, be engaging, be funny, be scary, be theatrical – the list of recommendations goes on and on. What doesn’t usually appear on the list: Unleash bugs on the audience.

Bill Gates used this last technique to great effect in his talk at this week’s TED Conference in California. While discussing the idea that malaria research is underfunded because the disease generally only affects people in poor countries, Gates opened up a canister of mosquitoes, telling the audience that it shouldn’t just be poor people who get to experience this.

Naturally the mosquitoes weren’t carrying malaria. And Gates’s mood was humorous, not hectoring. His very real and annoying visual got across his point better than words alone would have done. Though it’s worth cautioning speakers: There are a lot of things Bill Gates can do that normal humans can’t.

Take a look at the whole speech if you have time (it’s a little under 20 minutes). Gates also explores what makes a great teacher, and in a surprisingly candid moment he equates bad teachers to factory workers turning out “crap.”