I really need some suggestions

. Bella is almost 5 months old. She is gated in the kitchen (a large area), with her crate, toys, food and water while we are at work and nobody is home. I don't lock her up because I feel bad

. So, the past couple of weeks she has been digging and chewing holes in my lanoleum floor in the kitchen. I wish I had a video camera on her because I am stumped on how she is managing such a task! So far there are 3 nice size holes. I want to replace the floor, but I don't want her doing it again, so, do you helpful YTers have any suggestions, and maybe some reasoning on why she is doing it???
Thanks!!