Move group of files into subdirectory

Question

I want to move some ssh keys into a backup file. Specifically, I want to move id_rsa* into key_backups/, a subdirectory of .ssh. mv id_rsa* key_backup/ gives me back

usage: mv [-f | -i | -n] [-v] source target
   mv [-f | -i | -n] [-v] source ... directory

But I feel like what I'm doing is of the second variety...

EDIT

total 64
drwx------  11 chrismaddox  staff   374 Apr 30 14:12 .
drwxr-xr-x+ 56 chrismaddox  staff  1904 May  5 11:05 ..
-rw-r--r--   1 chrismaddox  staff    61 Apr 10 13:11 config
-rw-------   1 chrismaddox  staff  1766 Mar 15 14:07 github_rsa
-rw-r--r--   1 chrismaddox  staff   393 Mar 15 14:07 github_rsa.pub
-rw-------   1 chrismaddox  staff   668 Mar 16 14:11 id_dsa
-rw-r--r--   1 chrismaddox  staff   623 Mar 16 14:11 id_dsa.pub
-rw-------   1 chrismaddox  staff  1679 Mar 16 14:28 id_rsa
-rw-r--r--   1 chrismaddox  staff  1679 May  5 13:00 id_rsa.pub
drwxr-xr-x   2 chrismaddox  staff    68 Mar  8 16:38 key_backup
-rw-r--r--   1 chrismaddox  staff  3188 Apr 30 15:36 known_hosts

Answer 1

$ ls
id_rsa  id_rsa.pub  key_backup  known_hosts

$ mv id_rsa* key_backup/

$ ls
key_backup  known_hosts

$ ls key_backup
id_rsa  id_rsa.pub