This is good advice. In some areas, treatment will not be necessary. In others, people lose a lot of bees due to varroa. You need to learn how to tell if the infestation is low, medium, or high -- and this will depend on the time of year. A few mites do not mean the hive will die. Lots of good advice online on how to count the mite levels.I would do a sugar roll to check your mite load, then treat if necessary.