Asexual reproduction is with one partner
Keep in mind humans can’t reproduce asexually only sexually
A pyramid of energy can never be inverted because energy decreases by tenfold each level. This can't be reversed because energy can't just increase by tenfold. It has to come from somewhere.
If want a direct answer it would be the decrease in mice, but if you want to get technical the decrease in grain spills caused mice to leave so that would be the indirect cause