Like cockroaches after a nuclear fallout, or rubberneckers after a car crash, those insects tokens always seem to pop up after a big disaster....
By some miracle of uninspired design, there are not one, not two, but three cards that pump out insect tokens equal to the amount of damage they take. Now, this isn't a bad way to deter an opponent's attackers, as giving you a huge swathe of creatures is not exactly desirable. Add in Swarmyard and he's really in a tight spot, as all of the insect-producers are insects themselves, meaning you can use them turn after turn for as little as a tapped land.
A deterred opponent is not necessarily a cooperative one, though, and one armed with flyers or direct damage can simply ignore your bug pinatas. Sometimes you have to take matters into your own hands. If your come prepared to blast your own token-producers, there's no heftier payoff than Shivan Meteor, which gives you 13 creatures for five (or maybe three!) mana. Blasphemous Act does one better, nailing all of your critters at once (how does 26 creatures sound? Or 39?) while simultaneously wiping your opponent's board. All this for potentially as little as one mana!
As this is essentially a combo deck, you need a way to get your pieces, and Skullclamp is a huge help along the way. All the tokens you produce are 1/1s, meaning they can all be clamped to draw you into that crucial Blasphemous Act. Thornscape Familiar is a fellow Insect that makes your burn spells cheaper, helping you fire off sooner.
