how can i get my mom to buy me a rat ?

how can i get my mom to buy me a rat ?
i get all As i do all the chores in the house and i do research and i even got my own rat cage

This is what i did to get a hamster: (My mom is hard to convince and this worked!) Here are some tips:
1. keep your room clean chores around the house to get extra money so u can buy the stuff yourself
3. Show responsibility
4. be mature
5. write essays and add up the total of all the supplies you need. It makes you look responsible 😉
6. they only cost $10-$20
7. they dont smell unless u dont pick up their pee and poop
8. they DONT carry diseases if you get them from a reliable pet store
9. dwarves are smaller so they should be easier to deal with and their poop is smaller 😉

Good Luck!