The one cat we have never seen use other trees in house was in bottom cave with in seconds of piece being removed from box! All SEVEN the cats love it! I own another product & had a knock-off, which this one replaced. For the few extra $'s buy (any model) it out lasts other brand by 2x+. This model has held up well to the full grown male cats chasing each other up it. (StandingStood OK, Did not fall over) Shakes sightly yes but these are FULL grown males. I do have unit in a corner. Best price on web here!