Random, CPU Spikes with minimal users online.

I'm having one heck of a time trying to find out where / how this is happening current ifTop:

~~http://i.imgur.com/5qbyO4L.png" />

Here's what my CPU is looking like, last night again went through the roof with no users:

~~http://i.imgur.com/OkhKwDL.png" />

I've tried playing with apache but that doesn't seem to be the issue, apache www-data process just shoot up to 96%.. Site is crawling to say the least.~~~~