Quote - I mean, take a Hippo for example, what on earth does a female Hippo have that makes a male Hippo think ... OMG ... look at that!

And what about Goldfish?  They all look the same, it's not like female Goldfish have anything different that is visible to attract a male Goldfish, is it?  Goldfish don't have breasts and shapely things to distinguish them and make them attractive to a male Goldfish!

This smells rather troll-icious. However, I'll humor you for the moment:

Quote - Sex pheromones are pheromones released by an organism to attract an individual of the opposite sex, encourage them to mate with them, or perform some other function closely related with sexual reproduction. Sex pheromones specifically focus on indicating females for breeding, attracting the opposite sex, and conveying information on their species, age, sex and genotype after emitted by males. Volatile pheromones are characterized as sex pheromones or defensive pheromones and usually form a specific odor and are focused on alarm sensitivity.[1] Non-volatile pheromones, or cuticular contact pheromones, are more closely related to social insects as they are usually detected by direct contact with chemoreceptors on specific parts of insects (i.e. antennae, feet).

You should know this if you've ever taken a biology class.

Humans have the same thing, it's just a bit more complex with us and with many other factors involved. 

 

~Shane