Pupils at St John's Hill School will soon know what rats and other predators are lurking at the popular Virginia Lake reserve.
A group of 10 participants in the Schools Halo Project put 50 tracking tunnels in place there on June 25.
Inside each tunnel is a non-toxic peanut butter lure on an ink pad. Animals that investigate the lure leave their footprints behind in the tunnel.
The children picked up the tunnels on June 27, Bushy Park Education Group co-ordinator Robin Paul said.
Conservation Department community ranger Scotty Moore will read the information left behind by the animals' footprints, and the children will convert it to spreadsheets and report it to Whanganui District Council.