Solved Custom mob drops problem

For some reason CaveSpider and Spider interact with each other?

Cavespider drops spider head and cavespider head but spider only drops spider??

Code:

Code (Text):

    //CaveSpider
    @EventHandler
    public void CaveSpider(EntityDeathEvent event){
        Configuration config = configGetter.getConfig();
        if(config.getBoolean("CaveSpider")){
        ItemStack head = new ItemStack(Material.SKULL_ITEM,1,(short)3);
        SkullMeta meta = (SkullMeta) head.getItemMeta();
        meta.setOwner("MHF_CaveSpider");
        meta.setDisplayName("CaveSpider Head " + config.getString("PerCaveSpiderHead") + "$");
        head.setItemMeta(meta);
        if(event.getEntity() instanceof CaveSpider){
            event.getDrops().add(head);
        }
        }
    }
    //Spider
    @EventHandler
    public void Spider(EntityDeathEvent event){
        Configuration config = configGetter.getConfig();
        if(config.getBoolean("Spider")){
        ItemStack head = new ItemStack(Material.SKULL_ITEM,1,(short)3);
        SkullMeta meta = (SkullMeta) head.getItemMeta();
        meta.setOwner("MHF_Spider");
        meta.setDisplayName("Spider Head " + config.getString("PerSpiderHead") + "$");
        head.setItemMeta(meta);
        if(event.getEntity() instanceof Spider){
            event.getDrops().add(head);
        }
        }
    }