If you want to know what animal a poo belongs to, you could take a look at this video from the Wildlife Trusts.  

There are 46 Wildlife Trusts in the UK, from Scotland to Alderney and North Wales to Norfolk, Cornwall to Cumbria.  They are all working hard to bring wildlife back, and to empower people to take action for nature.   You can find your nearest Wildlife Trust here. 

The Trust explains that signs animals are in an area can be a good start to discovering who has been visiting. 

Ecologistsi rely on animal signs - they help them understand the behaviour of many animals, and gives them an idea of the numbers in an area.   It all helps to build up a picture of what animals are where.

There's more information about animal poo here.