It seems that there is a vast number of couples who are only looking for a female to play with them. For those who have the illusion that it might be easy, let me dispel it: it is not! There is a reason why they are called unicorns.
Why is it so hard to find them?
Statistically, there is probably one single swinger female for a hundred or more couples. There are several reasons why they are so rare: first of all, you have to be really brave to announce that you are a single swinging woman looking for a couple. Not every woman, even if she secretly wants it, will make this wish public. Secondly, a woman that wants to swing may find it easier to do it in a couple, so many of them partner with a male for swinging adventures which means that they are not single any more. Thirdly, some of them may still have their single female profile on, but they have already found the couples they have been looking for for the time being.
All this drastically reduces the chances for couples to find a single swinging female.
We have had such 3somes occasionally, when the opportunity presented itself, but we never actively looked for a single girl on purpose. From what we hear from our swinger friends, it can be a rather frustrating experience.
There is another side to the whole single swinger woman affair. A lot of couple say they are only looking for a woman because the husband cannot get over his jealousy in picturing his wife with another man. This usually happens in newbie swinger couples. Once they get more experience, husbands realize that it is exciting to see their wife playing with another man and they finally agree to accept couples. And this is what most of the swingers do: couples in 4somes and moresomes. To us, playing with other couples is more fulfilling than meeting single women.