Centipedes sometimes bite, producing mild to more serious reactions in people, but even so are not considered true pests in the garden. These like moist, protected places and usually eat small insects. Centipedes have brown, rather flattened bodies, and their legs are arranged in a pair for each body segment. The length of the creature determines the number of legs, so you may see 30 or a few hundred. Those here are in the 1-inch range, however.
Centipedes have venomous claws that they use to snare their insect victims.
The key to lavender's success here is sun, a sandy soil and minimum water. I've been more successful growing lavender in containers, because pots provide quick drainage and those that are cold-tender can be moved indoors during freezing weather. You should also pay attention to type. There are English, French and Spanish lavenders that will grow in our gardens. English lavender is usually treated as an annual here.