What do the tails of the locusts in Revelation 9 look like?

Les explains that America has never had to come under the attack of swarms and clouds of locusts, but in the Middle East locusts can cloud out the sun and roar so they are heard coming. He says these creatures will be so numerous and huge that the sound of their wings is like many chariots. Verse 10 gives them the ability to sting like a scorpion: they have tails like scorpions with stings in their tails, and their power is to hurt men five months per sting, which is beyond comprehension. Les notes they also have a king over them, the angel of the bottomless pit, named Abaddon in Hebrew and Apollyon in Greek, meaning the destroyer; he is probably one of Satan's cohorts, not Satan himself. Then one woe is past, and two more follow.