efecto hover

#menu{
height:100px;
width:100%;
text-align:center;
}
#menu a img{
width:80px;
height:80px;
}
#menu a{
display:inline-block;

}
#menu a:hover img{
width:90px;
height:90px;
-webkit-transition: all .3s ease-in-out;
-moz-transition: all .3s ease-in-out;
-o-transition: all .3s ease-in-out;
-ms-transition: all .3s ease-in-out;
transition: all .3s ease-in-out;
}