I like to walk this 2.9-mile (4.7km) route each spring to see if I can watch the green tiger beetle.
It is one of the most thrilling beetles in Britain.
It lived on Kingley Vale, but became extinct there in 1986.
It likes dry, hot, south-facing open land like that of the heaths and downs.
It is a brigand in a green cloak with yellow patches.
It pounces on flies, and you can play with it by flipping a tiny pebble nearby when it will run and glide at great speed and pounce on the bait.
Try it here on the sandy heathlands from April to June. Park at New Road car park between Heyshott and South Ambersham: SU914197.
The Serpent Trail runs on blue bridleway arrows south-west across the plateau, passing a trig point after 300 yards.
The heath was once part of the Thames estuary millions of years ago although the river flowed back to the Atlantic then.
After passing beneath power cables, on which a stonechat sometimes perches, bear left downslope to the Hoyle stream which has arisen near Gadd’s Bottom a mile-and-a-half to the south under the downs.
Another active insect found here is the wood ant, whose communities of thousands construct nests a yard high out of bits of plant.
Talking of insects again, a tiny wasp hereabouts makes a nest the size of a rabbit dropping out of dried mud and attaches this to a heather twig. That is the potter wasp.
Curiouser and curiouser, said Alice. This is a wonderland and no mistake.
Keep forward under the pines in which you can hear firecrests and goldcrests singing if you have excellent hearing.
Reaching the road turn left, and again left at the next junction.
You are under woodland all the time and there is a chorus in spring of chiffchaffs, blackcap warblers, woodpeckers and robins most of the day.
Reaching Wiblings Farm at another road junction, turn sharp left on blue arrow, into a woodland gulley going northwest.
The total road walk has been half-a-mile.
After 350 yards keep left at footpath junction, rejoining the Serpent Trail which goes near to Graffham Court.
Sharp left near this house, and stay on the Serpent Trail which now turns southwest.
This land is all rather boggy in wet weather.
Talking of insects again, this is the place to see that blue jewel of the holly trees, the holly blue butterfly whose caterpillars feed on the holly flowers.
Again, that is in spring, which isn’t far away.
After about 800 yards you reach your outgoing path near the Hoyle stream again so turn right, back across the heath.
By the way, in only another month, the first hobby falcons will begin to arrive back in England to breed, and you could easily see one here, one of the many Sussex sites at which they breed.
And, talking of insects, that is part of their diet here: butterflies, beetles and dragonflies.