Iolo Williams explores the wild side of towns and finds birds and animals that have adapted to life on the street. They've discovered it's a great place to get food as well as a safe place to raise a family. Some commute daily to town. Birds simply fly above the traffic, while four-legged animals use their own 'rat' routes. For these wildlife townies, the street is a place called home. In his first wild town tour, Iolo stumbles on tawny owls in residence in an Abertillery chimney. They've been living there for over a year. Rats have their own thriving colony in the centre of Swansea; few humans passing by notice. A fox family is living in an allotment in Cardiff. The vixen has raised three healthy cubs. Little wonder with all the healthy veg and grubs around. In Wrexham, a pair of extraordinary dippers are living in a culvert. They fly underground below shops, offices and flats to get to different parts of town. Also in the programme, Iolo finds the best-fed swans in Wales, a heron comes to a Llanberis garden for his daily diet of junk food, and in Deganwy, crows are given an IQ test.