Spider hatchlings

I saw this bunch of spider hatchlings just under the knob of someone's door curled up in a tight ball. When I turned the knob to go in, it disturbed them and they scattered in every direction. Stuff of nightmares really. The awesome thing was when I left the house they were all back in a lovely tight ball again, ready to scare their next victim. Should've taken another pic but I was visiting a client and was afraid they would be watching and wondering 'why's that funny bloke taking pictures of our door knob?'