There are buds and new leaves burgeoning on the trees, there are daffodils and daisies and coltsfoot, there are cuckoo flowers and cuckoos to come  – and then there are bats. Of all the signs of spring, it is the quiet, almost imperceptible, re-emergence of the last in that list that I love the most.

Swinging open my door this evening to let the dog out, three small bird-like shapes whisk across my eyeline and up into the twilight. Pipistrelles, soprano pipistrelles I think, their dancing around the gutters of our house silhouetted against the half-light of dusk. 

If the air is still enough, as it is tonight, it is possible to hear a faint leathery flittering of wings, but that’s all. My youngest son has been learning about echolocation in school and watches with me. We are unable to hear the clicks and squeaks that bounce off the bats’ surroundings and back to them, telling them where the house is, where we are, where the flies are that they seek. The sounds that bats emit are so high-pitched they are invisible to us, just as the bats themselves fade into the night as it deepens.

I would love to know where they spent the winter, what wee cool nook they found sheltered enough to hibernate in. Their fur is dark and brown enough that they could disappear into any small cleft in the woods, blending into woodpecker holes, or the hollows left by broken branches. Or they could have found some quiet spot in the eaves of the workshed, or even the house.

Over and over again I think of the word ‘synanthrope’: from Greek syn, ‘together with’, and anthropos, ‘man’ – creatures that are wild, yet whose ongoing survival benefits from sharing space with humans.

As with many species, the natural habitats of bats have declined as human habitats have expanded. And so bats have adapted to us, learnt to make our homes theirs too. Despite that adaptation, The Bat Conservation Trust highlights that numbers have declined over the last hundred years. Bat roosts are now protected by law in the UK, which means that if I were to find that the roost is in our house, there it would stay.

Even if I wasn’t already naturally fond of these creatures who have clung on, the Trust’s website is reassuring that they pose little risk. Unlike mice, bats don’t chew pipe-lagging or wires, and their droppings harbour no known health risks and will simply crumble to dust. Their presence generally has no direct impact on our lives.

In fact, silent as they are to us, if I wasn’t outside this evening I might not have noticed them at all.