Dog yelp and can't place blocks

Yesterday some people I invited started griefing by spawning tons of animals (horses and wolves) After I was able to kick them and keep them out, I noticed a certain area of my world will not allow anyone to place blocks. It will show for a split second and disappear and not leave inventory. Also When running fast or flying you can hear a dog yelp as if it was getting hurt. I made a copy but the copy does the same thing. This is rather annoying.