Start with determining their age, then decide if you should leave them with mom, take them in, or call the BC SPCA. If they are very young, it's safest to leave them in place until you can determine whether their mom is still caring for them. If you do take them in, their care will depend on their age.
Learn when to wait, when to act and how to care for kittens you find, watch our video:
https://youtu.be/3go2sUmhytU