Реализовать рост змейки в игре

помогите, пожалуйста! как я могу сделать рост змейки когда она съедает шары?
код:

import time
import random

from tkinter import *

import os

eaten = 0

x = random.randint(0, 350)
y = random.randint(0, 450)
r = 10

foodPos1 = x - r
foodPos2 = x + r
foodPos3 = y - r
foodPos4 = y + r

x1 = 80
x2 = 100
y1 = 80
y2 = 100
moveX1 = 10
moveX2 = 10
moveY1 = 10
moveY2 = 10
root = Tk()

navigation = ''

root.title('Змейка 2024')
root.geometry('350x450')

canvas = Canvas(root, width = 350, height = 450)      
canvas.pack() 
canvas.create_text(50,20,text='съедено: ',font="Verdana 12",fill="black")  
eat = canvas.create_text(95,20,text=eaten,font="Verdana 12",fill="black")     
snake = canvas.create_rectangle(x1,y1,x2,y2, fill="green") 
food = canvas.create_oval(foodPos1, foodPos3, foodPos2, foodPos4)

BX = random.randint(0, 350)
BY = random.randint(0, 350)
barpos1 = BX - r
barpos2 = BX + r
barpos3 = BY - r
barpos4 = BY + r
barrier = canvas.create_rectangle(barpos1, barpos3, barpos2, barpos4, fill="gray")

def game_over():
    global eaten
    f = open("ваши рекорды.txt", "a")
    f.write(str(eaten))
    f.close()
    Window = Tk()
    canvas = Canvas(Window, width = 350, height = 450)
    canvas.pack()
    canvas.create_text(200,180,text='GAME OVER',font="Verdana 12",fill="red")  
    root.destroy()

def move_up(event):
    global navigation
    if navigation != "down":
        navigation = "up"
def move_down(event):
    global navigation
    if navigation != "up":
        navigation = "down"
def move_right(event):
    global navigation
    if navigation != "left":
        navigation = "right"
def move_left(event):
    global navigation
    if navigation != "right":
        navigation = "left"

def draw():
    global navigation
    global moveX1
    global moveX2
    global moveY1
    global moveY2
    global x1
    global x2
    global y1
    global y2
    global snake
    global x
    global y
    global food
    global eaten
    global eat
    global barrier
    collision = canvas.find_overlapping(x1, y1, x2, y2) 
    if food in collision: 
        canvas.delete(food) 
        eaten += 1 
        canvas.itemconfig(eat, text=eaten) 
        x = random.randint(50, 300) 
        y = random.randint(50, 400) 
        food = canvas.create_oval(x - r, y - r, x + r, y + r, fill="red")
    collision1 = canvas.find_overlapping(x1, y1, x2, y2) 
    if barrier in collision1: 
        game_over()
root.bind('<Up>', move_up)
root.bind('<Down>', move_down)
root.bind('<Left>', move_left)
root.bind('<Right>', move_right)
if navigation == "up":
    y1 -= moveY1
    y2 -= moveY2
if navigation == "down":
    y1 += moveY1
    y2 += moveY2
if navigation == "left":
    x1 -= moveX1
    x2 -= moveX2
if navigation == "right":
    x1 += moveX1
    x2 += moveX2
canvas.delete(snake)
time.sleep(0.1)
snake = canvas.create_rectangle(x1,y1,x2,y2, fill="green")
root.after(10, draw)

draw()

root.mainloop()