It's a Scutigera sp. or House centipede. I see them all the time in my basement and garage (at least the ones the cats haven't gotten to yet ) They get to about 1.5" long (at least the ones here). They're cool to watch and really blast through small crickets and roaches. They can climb smooth surfaces though, so watch when you open your container it's in.....and as you've probally realized by now they're fast as hell.