Hello, this is Dr. Benedetta,and I would like to help with your question.
Dogs often eat grass to help themselves to vomit, when they have eaten something that they should not have.
The ants and bugs are not what is causing the growling, and pain, but whatever else was there, and the grass itself.
At this point, y\the best thing to do is to take Rousey to a veterinarian, where they can assess her, maybe take radiographs, , maybe induce vomiting, if she needs to get rid of the grass and/or other items in her belly.
If she is bloated and in pain, I would not wait at all, as there is always a risk for bloated, twisted stomach