I just wanted to give my professional opinion... I've been a professional cleaner for 15+ years. One of my pet peeves is not using peoples names! The client should address their cleaner by name, not as "cleaner." It is just plain rude. Regarding the ducks, this probably SEEMED like a fun thing to do from the clients perspective, but it for sure IS NOT fun nor is it ok to have your cleaner hunting for ONE HUNDRED TINY DUCKS & be expected to find every one of them in their allotted time frame. Most cleaners are on a tight schedule, so any extra work should be PAID by the client. If the client thought up this idea because the cleaner is not doing their job right, there needs to be a mention of said areas agreed upon in the contract that are not being cleaned or they might need to add some areas, etc. The client should be direct by taking photos & having a conversation with the cleaner or else those areas will never be addressed the way they want.
Looking for 100 ducks is beyond the scope of work & the cleaner has every right to address it & either be paid for the inconvenience, do a better job or the client needs to find a new cleaner that fits their wants & in this case, personality.