Click effect in Android

i have a code for only a background for my buttons...but when i running the code, i dont see the effect of click in my buttons! below, i show you my xml file for the background. Thanks!

<?xml version="1.0" encoding="utf-8"?>
<layer-list xmlns:android="http://ift.tt/nIICcg">
    <item android:left="5dp"
        android:right="5dp"
        android:top="5dp"
        android:bottom="5dp"
        >
        <shape
            xmlns:android="http://ift.tt/nIICcg"
            android:shape="rectangle">
            <solid android:color="#ffe49713">
            </solid>
        </shape>
    </item>
</layer-list>