Attractant Life Expecatancy
 

Okay, so for those of you that are more knowledgable than I am on the use of attractants... ie Deer co Cain, Cmeer Deer and products such as those.
Are there / is there a life expectancy of the product once it is used in the field? I know products have shelf life while they are still in the container. But what about once they are used? If they are sprayed are they only good for 30days? 60 days? I have a feeling that the poweres/pellets will of course last a bit longer, but its the sprays that I'm curious about.

Thanks
Alex