they are designed so that you cant see them when they attack.
so you level one people
BEWARE
I don't think it's possible to naturally meet a Deathclaw in the wild at level one. Perhaps if you go somewhere where they're designed to spawn, like Old Olney or the Deathclaw Sanctuary (Hurr).
Although, really, as long as you have a dartgun these things are pathetic. One shot and they slowly cripple walk their way over to you. Gives you plenty of time to shoot them from a distance and walk back from them. This is why I allways carry my dartgun and have it in my hotkeys.
It's the Albino Radscorpions that annoy me though, since they're able to do plenty of damage and seem to be me more resilliant to guns. Plus, the dartgun will cripple them, but they're still faster than you while crippled, or so it would seem. :/