Cedar chips or lemon

Hello Neil, good question and thanks for the comments about the site.

I’d say it’s doubtful that these methods would repel fleas. I need to dig further into natural deterrents, such as essential oils. Unfortunately, studies done against fleas are sparse. However, there’s some evidence that these types of compounds do have some insect repelling properties (studies done on other insect species).

Personally, I feel that the kind of articles you mentioned are just trying to capture web traffic by pandering to the “natural” trend. I’ve never seen them reference any actual studies or reputable literature.

Here’s an journal article which discusses botanical compounds briefly:
Biorational Approaches to Flea Suppression: Present and Future

Here’s the relevant snippet:

The botanical compounds pyrethrum, sabadilla, and rotenone have been recommended for flea suppression (Bishopp 1921). Limonene (Rink & Fee 1986) and linalool (Rink et al. 1988) have been labelled for flea control. The potential exists for the development of other herbal extracts as pulicides, particularly those with folk-history such as the aptly named fleabane and pulegone from certain plants (Chatterjee et al. 1968, Sudekum et al. 1992, Nicholson 1995). Neem also has been found to be toxic to fleas (Kilonzo 1991).

So, if I was going to experiment with natural deterrents, I wouldn’t start with cedar or lemon. I’d choose those mentioned in this article, such as neem, fleabane, or pulegone.

Also, keep in mind, effective repellents may prevent some bites, but they’ll do little to end a current infestation. 95-99% of the infestation is composed of pre-adult stages in the environment.

As a warning to anyone reading this: Be careful when applying essential oils to your skin, or your pets’ skin. Many cause irritation and some can be toxic. Do your due diligence and research before putting members of your household at risk. Natural isn’t synonymous with safe.