Arduino Robot

so here is the code

#include <AFMotor.h>

AF_DCMotor motor1(1); 
AF_DCMotor motor2(2); 
AF_DCMotor motor3(3); 
AF_DCMotor motor4(4);

void setup() {
  Serial.begin(9600);           // set up Serial library at 9600 bps
  Serial.println("Motor test!");
  
  motor1.setSpeed(255); 
  motor2.setSpeed(255); 
  motor3.setSpeed(255);   
  motor4.setSpeed(255);     
}

void loop() {
 
  Serial.print("for");
  motor1.run(FORWARD);  
  motor2.run(FORWARD);
  motor3.run(FORWARD);  
  motor4.run(FORWARD);  
  delay(5000);

  Serial.print("back");
  motor1.run(BACKWARD);
  motor2.run(BACKWARD); 
  motor3.run(BACKWARD);
  motor4.run(BACKWARD);    
  delay(5000);
  
  Serial.print("tack");
  motor1.run(RELEASE); 
  motor2.run(RELEASE);  
  motor3.run(RELEASE); 
  motor4.run(RELEASE);  
  delay(5000);

}

When i use it look what i get :

Why is it doing that to go to the front??