My elderly parents have lived in same house for 47 years, both in very bad health. A new neighbour one side moved in 4 yrs ago. She has lots of pets; cats dogs and birds. The front and back gardens are full of wood general rubbish. They have an aviary too. The smell and noise is unpleasant and there are also rats.
Contact the Env Health first. They have powers to deal with statutory nuisances and potential pest issues. There are some distinct issues to look into by the sounds of it:
(a) birds possibly contributing to rat activity;
(b) noise from animals (including birds);
(c) rubbish accumulations (that may allow harborage to rats/mice);
(d) odour from animals.
Alternatively, the situation (collectively) may amount to an anti-social behaviour issue – again, this should be able to be channelled through your EH department.