Wild Mus musculus response on two different essential oils with high repellent potential

Several herbal products have already been confirmed to have impact on rodent diet or behaviour. Some of them, rich in terpenes, have shown repellent effects. In that context, we evaluated the repellent activity of fresh and flat baits containing two different concentrations (0.03125% and 0.0625%) of commercial Melaleuca alternifolia and Cymbopogon martinii essential oils (EO) of determined chemical composition (GC-FID and GC/MS) against house mice (Mus musculus). The repellent effects of all tested baits varied depending on mice gender, bait freshness, and content of EO in baits. Baits with the higher concentrations of M. alternifolia and C. martinii EOs had the lowest preference indexes on the 1st day of exposure of both males and females to fresh EO baits [-0.77 and −0.88 (males) and −0.62 and −0.98 (females)], respectively. Baits with the lower content of M. alternifolia EO had an index value of −0.71. Long-term repellent effects can be achieved by using the higher concentration of either of the two tested EOs, while short-term effects can be expected from the lower concentrations.