Final answer:
Walking stick eggs have a unique reproductive strategy where they are dropped on the ground, rather than being laid in water, trees, underground burrows, or nests.
Step-by-step explanation:
The question regarding the unusual feature of walking stick eggs focuses on their reproductive strategy. Unlike amphibians that lay their eggs in water or birds that lay theirs in various forms of nests, walking stick insects follow a different pattern. Walking stick eggs are not laid in water, trees, or underground burrows. Nor are they laid in nests like those of many birds. Instead, walking stick insects have evolved a unique strategy where they drop their eggs on the ground, often in leaf litter or other ground cover. This can make it harder for predators to find them and also provides a moisture-rich environment for the eggs to develop. Once the eggs hatch, the young walking sticks are on their own to survive and grow.