What happened

I made 2 1gal batches of mead. 1- 3lbs honey,apple cider, spices, fresh orange zest. the other 3lbs honey whole orange(sliced) and 2 cloves. the 2nd is doing great. the first looks to have made lots of yeast but is just laying on the bottom and no action on the airlock. i did add yeast nutrient to both as well. I forgot to sanit. the orange i got the zest from. would the pesticieds kill the yeast? What happened?

Did you rinse off the orange before adding? I suppose pesticides could kill it, but I would doubt that just the amount of some zest would be enough. You can't rely on airlock activity to determine fermentation. There are so many different factors that can will cause or prevent airlock activity. Do you have signs of fermentation? Is the mead bubbling? Has the gravity changed? Is there a possibility the yeast was not good? Or was the same batch of yeast pitched for both meads?

If, like you said, it made a lot of yeast in the bottom, more yeast than you initially added, then I would say it's working. More yeast means they are multiplying, so they would still be alive and working.

Didn't rinse orange. no bubbles in the mead. about a 1" - 1 1/2" of snotty like substance on the bottom of the jug. i'm sure some of it is from the unfiltered cider the rest looks like the yeast that i pitched but a lot more. I pitched the yeast on Friday, the other batch with the other 1/2 of the yeast is blowing throught the airlock. haven't checked the gravity. i'll give it another 2 days and see what happens. if nothing then i'll be asking for suggestions. Thanks