A Sugar Trap is a creature living in the Deeps, specifically the Great Plain. They are a nuisance to people travelling past them, as the person might get tempted to follow the scent. They are large elongated and crusty pipes releasing sweet smelling spores when triggered by touching the tubes. In Deeper, Cal is almost killed by a sugar trap on the Great Plain. Luckily, Drake and Chester save him just in time.
It releases spores which grow roots into any flesh attached to and is triggered to release spores when touched.
Although not included in the book it can be concluded that there are several possible ways the Sugar Trap may have evolved. One theory is that the Sugar Trap is an evolved species of Cave Oyster that lives in underground streams and has an extension to its shell which leads above ground to attract prey. It is thought that if this theory is true, then the part of the cave oyster that is underground would be up to six ft. in length and width. When the spores have killed a victim and have derived the nutrients the Sugar Trap's tube would suck the spores back to consume the nutrients the spores collected.
Another theory is that the Sugar Trap isn't even an animal, and is actually a species of fungi which is very hard due to Calcium being present in its growth. It releases spores from itself which grow into another animal and when it dies it decomposes and the "Fungi" version Sugar Trap uses the new soil nutrients.