Sawyer ピカルジン虫よけ漁師用調合 4オンススプレーSP544

Q: I bought two bottles 3 years ago but don’t see a expiration date. Do they expire??

Our insect repellents have a shelf life of 10 years if properly stored in a cool, dry location away from UV exposure

Q: Does this help to deter or repel Spiders?

I use the "Permethrin spray" and it works well on all insect's.

Q: Do all 3 types repel against mosquitoes carrying Yellow fever? I only see yellow fever mentioned on the pump. But I would like to get the spray…

This product works against all mosquitos--to the degree that it is possible to repel them. The particular disease the mosquito may be a vector for doesn't affect how well this works.

Q: Can the pump spray be spread around with your fingers on areas that are hard to spray, like the back of the neck, or is it too dry to spread easily?

To me is yes , is not too dry to spread. You can pump and spray around back of the neck or spread with your fingers on areas that are hard to spray very easily, very easily....... And that is my opinion.