// duration[DUR_CONTROLLED_FLIGHT] makes the game think player 
    // wears an amulet of controlled flight

        }
        else if (!grid_is_water(new_grid) && grid_is_water(old_grid)
                 && you.species == SP_MERFOLK)
        {
            you.redraw_evasion = true;

        break;
    default:
        break;
    }
    switch (you.species)
    {
    case SP_MERFOLK:
        // Merfolk get an evasion bonus in water.
        if (you.swimming())
        {
            const int ev_bonus = std::min(9, std::max(2, ev / 4));
            ev += ev_bonus;
        }
        break;
    case SP_KENKU:
        // Flying kenku get an evasion bonus.
        if (you.levitates() == 1)
        {
            const int ev_bonus = std::min(9, std::max(1, ev / 5));
            ev += ev_bonus;
        }

    you.redraw_evasion = true;

    if ( !player_is_levitating() )

    if ( !is_levitating() )

    you.redraw_evasion = true;