Best Bay Area Hikes for Spotting Banana Slugs, Newts and Ladybugs After the Rain

The Bay Area has been drenched with rain from multiple atmospheric river storms these past few weeks.

But once we get a break from this rainy weather — as the National Weather Service forecasts this weekend — there’s a big upside: After rainfall is one of the best times to see colorful creepy crawlies out in nature. And right in time for Valentine’s Day, this is when they’re on the hunt for mates.

Keep reading for the best hiking trails in the Bay Area to hit after a wet spell to spot banana slugs, California newts and ladybugs. Just be sure to watch your step as you go.

Banana slugs on wet trails

Banana slugs are mostly water, relying on moist environments to stay alive. In dry conditions, these striking yellow molluscs retreat to cool and shaded areas. But right after the rain, you’ll find them gliding along on wet soil in California’s damp forests — powered along by the slime produced by cells in their skin that helps them move over dirt and leaves. This slime allows banana slugs not only to retain their moisture but also to defend themselves by producing mucus that numbs the mouth and tongues of any predators trying to nibble on them. The chemicals left behind in their slime trails also allow banana slugs to more easily find each other.

Banana slugs are scavengers that feed on dead leaves, mushrooms and animals, but they’re also decomposers that help recycle nutrients into the forest floor. They also play a key ecological role by dispersing seeds and spores.

These slugs are hermaphroditic, possessing both male and female reproductive organs. And while they mate all year round, they’re most active after the rain. Mating is a lengthy process that sometimes results in one slug biting off its mate’s reproductive organ — a process scientifically known as “apophallation.” They lay eggs under logs or leaves, but they’re not attentive parents: Banana slug hatchlings must fend for themselves.

Where to see banana slugs in the Bay Area after the rain

• Tilden Regional Park, Berkeley
• Reinhardt Redwood Regional Park, Oakland
• Muir Woods, Marin
• Henry Cowell Redwoods State Park, Santa Cruz
• Armstrong Redwoods, Sonoma
• Purisima Creek Redwoods, Half Moon Bay
• The Bear Valley Visitor Center, Point Reyes

California newts, looking for dates

In the winter rainy season, thousands of orange-brown California newts cross Bay Area roads, migrating from burrows to mating ponds. Like banana slugs, newts need moisture to survive — especially during this mini-migration season.

During the breeding season, male newts go through a dramatic change. Once in the water of the mating pond, they become bulkier, their tails flatten into fins to swim better, and they develop pads on their feet to allow them to clamp onto a female newt.

After mating, the newts produce clusters of eggs, which they sometimes munch on for extra protein. The eggs that survive grow into larvae and, after a few months, will leave the pond as adults — only to return when they themselves are ready to mate.

Where to see California newts in the Bay Area after the rain

• Sibley Volcanic Regional Preserve
• Reinhardt Redwood Regional Park
• Sunol Regional Wilderness
• Las Trampas Regional Wilderness
• In ponds and small lakes

Get more tips on spotting newts in the wild.

Ladybugs in loving clusters

In winter, when their food source is low, ladybugs cluster together in the millions to stay warm, conserve energy and protect themselves from predators. This is also an excellent time for them to find a mate — and for you to spot them in such numbers, called “aggregations.”

The species more commonly found in the Bay — for example, at Reinhardt Redwood Regional Park — are convergent ladybugs, one of 175 species native to California. The red color on their bodies is a defense mechanism against predators — a warning sign that they’re toxic. Over 5,000 species of ladybugs exist worldwide and come in different colors.

Where to see ladybugs in the Bay Area after the rain

The Stream trails at Reinhardt Redwood Regional Park in Oakland are a reliable spot to see ladybug aggregation. Hikers have also spotted aggregations at Santa Cruz Mountains State Park.

If you plan to see these colorful clusters, be sure to respect them by watching from a short distance. Collecting ladybugs from these aggregations is prohibited, as they might not survive their relocation.