A young girl looks anxiously at one of the objects in her tray. "If it's a leech, will it suck a human's blood, miss?" she asks, and is relieved to get no for an answer.
She and a dozen other ten-year-olds from Hillsborough Primary School in County Down are squatting on a boardwalk by a pond on a nature reserve by Lough Neagh, absorbed in identifying its contents under the expert guidance of Rosemary Mulholland, the reserve's interpretative officer.
Pond-dipping is just one of the many activities on offer at Oxford Island, which is actually a peninsula at the south-east corner of Northern Ireland's famous lough. The largest lake in the British Isles, it is rich in wildlife, folklore and a wonderful variety of habitats.
There are activities for pupils of all ages. For younger ones there are woodland walks to observe trees, animals and plants; trips through the meadows to identify wild flowers or study the butterfly lifecycle; nature awareness games; or bird-watching on one of the reserve's five hides.
A-level or BTEC students, on the other hand, come to look at the various problems involved in managing a nature reserve. They are shown how the staff aim to get a balance between the needs of people and wildlife, making sure that neither spoils the other's enjoyment of the place.
The Hillsborough children now move on from the pond to a hide overlooking Kinnegoe Bay, where cormorants, terns, reed buntings, shovelers, grebes and many other birds are found in abundance. There is great excitement as, through their loaned binoculars, the children watch a heron take off and rise majestically across the lough.
Experience is direct. "We're not keen on giving them worksheets, they get too caught up in them," Rosemary Mulholland says. "We'd much rather they just looked and enjoyed everything here, and did follow-up work back at school. "
Some of the schools she works with visit under the aegis of Education for Mutual Understanding, a key element in the Northern Ireland curriculum. "Occasionally the Protestant and Catholic schools want to be separate, but we make them work in mixed groups," she says. "Nature study is a great leveller. "
Groups also spend some time in the Lough Neagh Discovery Centre, which opened in 1993, and won an Interpret Britain special award last year. An attractive building on the reserve and at the water's edge, it houses audio-visual shows, some ingenious interactive games, and an exhibition devoted to the mythology, history, resources and ecosystem of the lough.
The history goes back to a Viking encampment on Oxford Island. As for mythology, there are tales of a submerged city flooded as a result of human greed; and a legend that the giant Finn McCool scooped up a lump of earth to make the lough and threw it into the Irish Sea, where it formed the Isle of Man.
Pollution is one of the central themes of visits to the lough. In the 1960s, blighted by algae blooms, Lough Neagh seemed on the point of dying. Today it is a thriving area for fishing (some of it illegal), and an internationally important centre for monitoring birds and protecting their habitats. Yet sewage, farm waste and chemicals still flow into the lough.
There is also a simulated shop containing products of the lake and its region. The well-designed exhibition is not only informative, but fun: there are games linked to water use and wildlife and, in the Ecolab, a restaurant that serves fish - as customers (the menu includes "Snail crunchies: a mollusc masterpiece worth diving five metres for").
* Lough Neagh Discovery Centre, Oxford Island National Nature Reserve, Craigavon, County Armagh BT66 6NJ. Tel: 01762 322205.