Martin Smith wrote:

As far as I am concerned you can come and collect as many as you like
from South East London, we have so many of them, but beware, a lot of
them are very mangy, I suppose since their diet will be a mixture of
discarded fast food, lots of that round here, and of course the
contents peoples bins. We fairly often find dead ones on our
allotments. They are not a healthy population at all.

Animals die. I don't think you can read too much into that, except that
there might be something poisonous on the allotment.