Eucalyptus, marigolds, and basil are three more popular choices. Eucalyptus contains strongly scented compounds, while marigolds are often planted around gardens. Basil is particularly convenient because you can keep it near a sunny kitchen window and use the leaves for cooking.

Rosemary, catnip, and lemongrass are also frequently mentioned. Catnip contains nepetalactone, a compound studied for its insect-repelling properties, while lemongrass contains aromatic compounds related to those used in some mosquito-repellent products. Rosemary provides another strongly scented option for patios and gardens.

Pennyroyal is traditionally associated with pest control, but it deserves extra caution. Pennyroyal oil can be highly toxic if swallowed and shouldn’t be treated as a harmless household remedy, particularly around children and pets. Essential oils in general also require care because concentrated products can irritate people or be unsafe for some animals.

Most importantly, simply placing these plants around your house isn’t a guaranteed way to eliminate mice, spiders, mosquitoes, or other pests. Their effectiveness varies considerably, and evidence for some popular claims is limited. For reliable prevention, combine plants with practical measures such as sealing cracks, repairing screens, removing standing water, storing food securely, and keeping areas clean. Think of these plants as attractive additions that may help discourage certain insects, rather than replacements for proven pest-control methods.