Hopefully, they take amount of plague into account. I do not know what the plague background levels are there currently (though some Montana locations have had enough for it to be noticed in recent years), but it appears to be a limiting factor for colony survival when above a certain point. <http://www.greatfallstribune.com/article/20131106/NEWS01/311060006/Ferrets-brink-UL-Bend> Sukie (not a vet) Ferrets make the world a game. Recommended ferret health links: http://pets.groups.yahoo.com/group/ferrethealth/ http://ferrethealth.org/archive/ http://www.miamiferret.org/ http://www.ferrethealth.msu.edu/ all ferret topics: http://listserv.ferretmailinglist.org/archives/ferret-search.html "All hail the procrastinators for they shall rule the world tomorrow." (2010, Steve Crandall) A nation is as free as the least within it. [Posted in FML 7955]