Been letting our cottage for 10 years. Don't get white or ivory towels - they disappear! Turquoise, purple and mustard don't. Don't get nice toothmugs - they disappear! Cheap plastic ones don't. I put a clause in the Terms & Conditions they have to sign when booking, stating that we have the right to terminate the holiday let immediately should we have any concerns regarding the welfare of farm livestock. Not had to use it so far but I don't let any guests around the sheds or pigsties. Even then, I once found a Mum watching her toddler attempting to stroke a boar - at mouth level! I have a map of the farm on a noticeboard above the kitchen sink showing exactly where they may go, along with a list of rules "which we hope will help to make your holiday enjoyable". These include Shutting Gates (although all the gates leading on to the lane are padlocked, just in case) and anyone who is or may be pregnant not approaching pregnant sheep. I always offer to show guests around the farm. Just like most folks, some are very pleasant and some you're very glad to see the back of. And never, ever, underestimate the amount of time it can take to clear up the mess left by 4 people who've been out for most of the week - our pigsties are a lot, LOT, cleaner than some people's houses, I'd guess.