[BethP1974]

Hi,
We have around 40 chickens and 8 ducks, who have free range on our 4 acre smallholding (although they don't go too far from the yard)
About a month ago one of our bantam cockerels died and then yesterday one of our bantam hens also died.
All the others seem fine, there were no signs of injury on either of them, they just seemed a bit quiet for a day, then died.
They are wormed (with medicated layers pellets)
Any ideas as to why they just died, and how can I tell if the rest are going to get ill?
Thanks

[Richmond]

Do they roost in a hen house at night? Could it have a red mite infestation? 
One sudden death may just be unlucky. Two in a relatively short time are almost certainly related in some way.  Age, illness, parasitic infestation ..... or a combination of all three.

[chrismahon]

My guess would be red mite in the coop. Bantams are much smaller and will therefore be more susceptible to die from the blood loss.

[Anke]

You don't say how old they were.... In my experience chickens are worse than sheep with their habit of just keeling over for no obvious reason. And a month between two deaths in a flock of 40 is unlikely to be a link IMO.

[Possum]

I tend to agree with Anke. If the bantams were a similar age it might just have been their time.