Weighing just 200mg, the fragile painted lady butterfly makes one of the most extraordinary migrations on Earth.

Every year, it travels 2,000 miles from the Atlas mountains of Morocco, through Europe, to the gardens of the UK.

Butterfly enthusiast Martha Kearney and a team of scientists follow the trail of these beautiful insects in an attempt to unravel the mystery of how they migrate, and why they embark on such a dangerous journey.

An army of amateur butterfly lovers across the country has been monitoring the arrival of the painted lady to the UK to help build a picture of our butterfly population.