<br/>For nanobugs to be "alive" they would need to be able to procreate, or have a nanofactory.  What if in the case of these "bugs" their factory has been destroyed.  They no longer have the ability to self-replicate, (their self-replicating assempler[diamondoid nanofactory] has been destroyed).  They must find a way to reproduce.<br/><br/><br/>They find the chemical sequences in the DNA that controls aging of humanoid lifeforms ONLY, (since DNA is a terciary chemical strand and they need all three chemicals to replicate)<br/><br/><br/><br/><br/><br/><br/>Though I think NosCorventius's idea of bug waste is kinda cool. :)