They are probably still around. They are a pest species that will get into any grains they can as well as other foods. Often times the only way to get rid of them is to get rid of all your cultures and start over. It is always easier to watch out for things and keep them out than to try and get rid of them. As you saw they were in your chicken feed so they can easily migrate. Its one of the reasons they are such pests.
Digby Rigby
DigbyRigby@exoticfeeders.com
http://exoticfeeders.com