I have one hen who is leaving a foamy mustardy looking poo. I found this guide on poo http://chat.allotment.org.uk/index.php?topic=17568.0 but the last picture under "normal", and the "worms" picture looks the same to me. I've never noticed this foamy poo until the last few days and my hens are 9 months old now, so should I give them all a wormer?