We have two senior (15 & 11) , I was surprised to find they won't stay out of this. They even love to play thru the holes with my grandson. Mind you, my cats are 13lbs and 19lbs - the 19lb one loves it the most! No trouble moving thru it and loves the lil toy. #RankBoosterReview #Sponsored #Pevor https://www.amazon.com/Pevor-Collapsible-3-Way-Tunnel-Toys/dp/B074FWHWTM