How to check the rotation

i gor a script for my animals so they can walk around the world but the problem is my rigidbody. i need it for my hp script so the animals can be killed but if u throw something at them, they fall down. i wanted to make a script wich checks if the rotation on the z is under or above 0, if the number is above or under 0 it should change the number to 0 back so the animal is not able to fall down but i dont know how to do it, can somebody help me?


using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class Animal : MonoBehaviour
{
public float movementspeed = 3f;
public float rotspeed = 100f;

public Rigidbody rb;

private bool iswandering = false;
private bool isrotleft = false;
private bool isrotright = false;
private bool iswalking = false;

private void Update()
{
    if (iswandering == false)
    {
        rb.isKinematic = false;
        rb.detectCollisions = true;
        StartCoroutine(Wander());
    }
    if (isrotright == true)
    {
        rb.isKinematic = true;
        rb.detectCollisions = false;
        transform.Rotate(transform.up * Time.deltaTime * rotspeed);
    }
    if (isrotleft == true)
    {
        rb.isKinematic = true;
        rb.detectCollisions = false;
        transform.Rotate(transform.up * Time.deltaTime * -rotspeed);
    }
    if (iswalking == true)
    {
        transform.position += transform.forward * movementspeed * Time.deltaTime;
    }
}
IEnumerator Wander()
{
    int rottime = Random.Range(1, 3);
    int rotwait = Random.Range(1, 4);
    int rotatelorR = Random.Range(0, 3);
    int walkwait = Random.Range(1, 4);
    int walktime = Random.Range(1, 5);

    iswandering = true;

    yield return new WaitForSeconds(walkwait);
    iswalking = true;
    yield return new WaitForSeconds(walktime);
    iswalking = false;
    yield return new WaitForSeconds(rotwait);
    if (rotatelorR == 1)
    {
        isrotright = true;
        yield return new WaitForSeconds(rottime);
        isrotright = false;
    }
    if (rotatelorR == 2)
    {
        isrotleft = true;
        yield return new WaitForSeconds(rottime);
        isrotleft = false;
    }
    iswandering = false;
}

}

transform.rotate;