A primary pupil on a day trip to the Falls of Clyde saw a crisp packet on the ground, turned to the guide and said: "People shouldn't do that. A bird or a hedgehog could get stuck in there and wouldn't be able to breathe," recalls John Ralston of Scottish Natural Heritage.
"It's when they say things like this that you realise they have learned something. It's great; it makes everything worthwhile."
This is the third year that Mr Ralston has organised a trip to the wildlife reserve in New Lanark for St Ninian's Primary in Edinburgh, and it is all part of a pilot education project which teaches children about the problems of wildlife crime and how to help prevent it.
The project is organised by the Partnership for Action Against Wildlife Crime (PAW), a multi-agency body that promotes enforcement of wildlife legislation in the UK. Wildlife crime - covering flora and fauna - can be categorised into three main types: illegal trade in endangered species, crimes involving native species which are endangered or of conservation concern (including killing species, taking them from the wild and destroying protected habitats) and cruelty to and the persecution of wildlife species.
During the past year, P5 pupils have been involved in a class project on one particular endangered bird, the peregrine falcon. They have had talks from conservation experts and prepared written work.
The trip to the Falls of Clyde, sponsored by Woods of Perth and the Scottish Executive, allowed the children to see peregrine falcons nesting in their natural setting. During a guided tour of the reserve, which is also home to rare brown long-eared bats and barn owls, aspects of the habitats and flora were pointed out.
The children also took part in a wildlife crime quiz, with prizes for the winners donated by the Scottish Society for the Prevention of Cruelty to Animals.
"It was a fantastic day," depute headteacher Deirdre Ralston says. "All of the kids were so absorbed by what they were being told.
"We did a lot of preparation about the peregrine falcon prior to the trip and when they saw it the awe factor was there. They got to see the mother, father and two chicks. The clarity through the telescope and binoculars was great. When one girl saw it, her mouth fell open."
The project is not just environmental; there is language work and moral education.
"It's lifelong learning. They will take this kind of experience with them," says Mrs Ralston. "As they grow older they will be more aware of other things going on in the wild."
Class teacher Louisa Campbell plans to continue the work in the classroom.
"Discussing the day and the things they saw really brings the project to life for them," she says.
Mr Ralston is certain that the visit will remain imprinted on the children's memories for years to come and that, in the long term, the awareness raised of the damage caused by wildlife crime will contribute to a greater respect of our wildlife.
Scottish Natural Heritage is working on ways to get more schools involved with the project. Mr Ralston says they are working on an information pack for children of any age, which will have games, quizzes and ideas for projects about how to care for the environment, and a website which will have classroom resources for teachers and provide project ideas.
Scottish Natural Heritage hopes that the pack will come out around September and the web-based package will be online by March, says Mr Ralston.
Ian Cornforth, the Falls of Clyde reserve manager, welcomes visits from schools. "The Scottish Wildlife Trust has been involved in PAW from the outset and has a strong commitment to its aims. We are keen to encourage youngsters to become involved in preventing wildlife crime by instilling in them a lifelong love and appreciation of wildlife, seeing at first hand the beauty of peregrines at the Falls of Clyde is instrumental in helping us achieve this end," he says.