So why would you let them get close to you?
One might think, "Hey, I should slow it down and shoot it's legs." This is wrong. Shooting their legs, even if crippled, doesn't slow them down.
Shooting their wings off, on the other hand, will. And considering the wings are more prevalent than the body most of the time in VATS (IE you most often have a higher chance of shooting their wings than their body) it's not exactly hard to do.
They usually come in swarms though. If you're a capable EW user, Meltdown will make quick work of the little buggers (pun was SO intended). Otherwise you might want to set up some mines and then lob some grenades. Although, with a pistol, high AGI and some Jet, you can VATS the wings off every one in a group then kite them as they slowly crawl on the ground toward you.