At the two week mark I'd be getting a bit worried. Frogs can go a while without food, but after that kind they should be getting really hungry. How well have you been keeping track of cricket numbers? They may have eaten at night. Speaking of night activity, are they at all more active before you head to bed? Anyway, if you haven't kept track of the crickets that's okay. A good indicator of whether they've been eating is poop. If there's fresh poop, they've probably eaten. If they haven't eaten they are probably starting look skinny. With a larger species I might suggest force feeding, but it stresses the frog(really bad if the frog is not eating because of stress.) and I feel like it could be dangerous for these small, dainty frogs.
Stress is one reason frogs may not eat. Frogs find high traffic areas stressful. To reduce stress you can cover the sides sides of the tank, make sure they have hiding places, and possibly move the enclosure to a low traffic area(if it is in a high traffic one.) With my toads, to calm them down I sometimes covered their terrarium with a bath towel(mine was green. I figure they would like green/brown/etc. Natural colors.), but my toads were eating already. I put it on them because they kept trying to hop out and bashing their faces into the terrarium wall.
To be honest, I havent yet had a frog that didn't eat, so I dont have a lot of experience. I'll look into some more info.
Edit: I have some more ideas.
1. What humidity are the frogs kept at?
2. What size crickets have you been feeding them? A good rule of thumb is too keep food items roughly equal in size to the space between the frog's eyes.