my snake game snake doesnt die when it eats itself?? kya galat hai 😅

bhaiya didi help 😅 i made snake game in python (pygame) at night after physics. its working mostly but when snake eats itself it doesnt die?? it just goes through itself like ghost. kya ye sahi hai?? my friend says my snake is immortal lol

here is the code (food wala part i removed to make it short, when it eats food i do snake_len += 1)

import pygame
pygame.init()
win = pygame.display.set_mode((600, 400))
clock = pygame.time.Clock()

x, y = 300, 200
dx, dy = 0, 0
snake_list = []
snake_len = 1
game_over = False

while not game_over:
    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            game_over = True
        if event.type == pygame.KEYDOWN:
            if event.key == pygame.K_LEFT:
                dx, dy = -10, 0
            elif event.key == pygame.K_RIGHT:
                dx, dy = 10, 0
            elif event.key == pygame.K_UP:
                dx, dy = 0, -10
            elif event.key == pygame.K_DOWN:
                dx, dy = 0, 10

    x += dx
    y += dy
    snake_head = [x, y]
    snake_list.append((x, y))
    if len(snake_list) > snake_len:
        del snake_list[0]

    for block in snake_list[:-1]:
        if block == snake_head:
            game_over = True

    win.fill((0, 0, 0))
    for bx, by in snake_list:
        pygame.draw.rect(win, (0, 255, 0), (bx, by, 10, 10))
    pygame.display.update()
    clock.tick(15)

pygame.quit()

sorry if indentation is little weird, i copied from laptop to phone. please dont tell my mummy i am doing this instead of rotational motion 🙏