def add_height_to_species(spcs, height=None):
    """Add to a string (spcs) a height using the ESX header friendly format
        ex: O3  =>  O3:42m
    """
    if height is None:
        height = ''
    elif type(height) == 'int':
        height = str(height) + 'm'
    return spcs + ':' + height
