Neon Tetras and Guppies

[Funny Pie]

Do these fish agree with each other, cause the guppies seem to be chasing the neons around, but then they chase each other around too, will i have a problem with this combination?

 

[Tokis-Phoenix]

Neons can be a bit nippy especially if you have delta tailed guppys(ones with the longest tail/fin type commonly available) but any fish's behavior can change if its under social or enviromental stress, so..;
a. How long has your tank been set up for and do you know about cycling a tank?
b. How many male and female guppys do you have, neons and any other fish?
c. How many gallons/litres is your tank?