I'd like to have my keyfiles leave memory after a certain amount of disuse. Is there a way to make ssh-agent expire keys faster? It feels like it keeps them in memory and not needing a passphrase for really long periods of time.
Can I set how long ssh-agent keeps keys in memory? 
ssh;ssh agent
Pass the -t option to ssh-agent or to ssh-add. The argument can be a number of seconds or use other time units.