Leopard Slugs Identification Guide

Leopard Slug Identification Guide

Physical Characteristics

Leopard slugs are one of the largest slug species in North America. They measure 4 to 8 inches long when fully stretched out. Their spotted pattern looks like a leopard’s coat, which is how they got their name. The body color is usually gray, tan, or light brown with dark brown or black spots.

The mantle is the fleshy shield that covers the front part of the body. This area shows the most spots. Behind the mantle, dark stripes run toward the tail. Like all slugs, they have two pairs of tentacles on their head. The top pair has eyes at the tips. The bottom pair helps them smell and taste.

You can also spot a breathing hole on the right side of the mantle. This pore opens and closes when the slug breathes. The bottom of the slug is whitish, which helps tell it apart from other species.

Similar Species

Leopard slugs look like several other large slug species:

• Great Gray Garden Slug (Limax cinereoniger): Darker color with a pale line down the back
• Spotted Garden Slug (Limax valentianus): Smaller with more even spotting
• Ash-Black Slug (Limax cinereoniger): Same size but no leopard-print pattern

Leopard Slug Behavior and Biology

Habitat and Movement

Leopard slugs come out at night and hide during the day. They like cool, damp places. You may find them under logs, rocks, leaf litter, flowerpots, or in cracks around buildings. They come out at night or when it rains to look for food. They are most active when it is humid.

These slugs move by squeezing muscles along their body. They leave a slime trail as they go. This mucus helps them move and keeps them from drying out. They also use the slime to find their way back to hiding spots.

Diet and Feeding

Leopard slugs eat many types of food:

• Dead and rotting plants
• Fungi and mushrooms
• Algae on surfaces
• Pet food left outside
• Other slugs

They will hunt and eat smaller slugs. This includes slugs that damage garden plants.

Reproduction

Leopard slugs have an unusual mating habit. Each slug has both male and female parts. When they mate, two slugs hang from a slime thread. They twist around each other in the air and swap sperm.

After mating, each slug can lay up to 200 eggs. They put them in moist soil or under debris. The clear, jelly-like eggs hatch in about a month. The baby slugs look like tiny adults. Leopard slugs can live 2 to 3 years.

Seasonal Activity

Leopard slugs are most active in spring and fall. They like mild temps and higher moisture. They slow down in hot, dry summers. In winter, they may go dormant. In areas with mild weather, they may stay active all year.

Managing Leopard Slugs Around Your Home

Prevention Strategies

Finding slugs indoors can be a nuisance. The best approach is to make your home less inviting to them:

• Reduce moisture: Fix leaky faucets, improve drainage, and use dehumidifiers in damp basements
• Remove hiding spots: Clear debris, leaf litter, and woodpiles from near your foundation
• Seal entry points: Caulk gaps around windows, doors, pipes, and foundation cracks
• Adjust landscaping: Keep mulch away from the foundation and trim plants that create damp, shaded areas

Physical Removal

For slugs already inside, you can remove them by hand:

• Look for slugs at night with a flashlight when they are moving
• Wear gloves and drop slugs into a container of soapy water
• Check under flowerpots, boards, and other hiding spots during the day
• Set traps using boards or damp newspaper that slugs will hide under

Control Methods

Several methods can help control slug activity:

• Copper barriers: Copper tape or mesh around raised beds creates a surface slugs avoid
• Iron phosphate baits: These slug baits are approved for use around pets and wildlife
• Dry borders: Gravel or crushed eggshell borders create terrain that slugs dislike
• Beer traps: Shallow containers of beer attract and drown slugs

When to Seek Professional Help

Most leopard slug problems can be handled with the prevention and removal methods above. However, if you have a large number of slugs around your foundation or they keep getting indoors despite your efforts, a pest control professional can assess the situation. They can identify entry points and moisture issues that may be attracting slugs to your property.

References

• Slugs and Snails - University of California Agriculture
• Slugs - University of Maine Cooperative Extension
• Leopard Slug - University of Maine Cooperative Extension
• Slugs - University of Alaska Cooperative Extension
• Limax maximus - Wikipedia