Make object not be present until spawned in?

So how do I make it that when I start the game, a specific physics body is not already present, but only spawns in when I push a button

I am using this button here 

local physics = require("physics") physics.start() physics.setGravity( 0, 5) local eggplant = display.newImage( scene.perRunGroup, "images/eggplant.png" ) eggplant.x = 70; eggplant.y = 100 eggplant.myName = "eggplant" physics.addBody( eggplant, "dynamic", physicsData:get("eggplant") ) eggplant.collisionType = "eggplant" -------------Remove eggplant button local widget = require( "widget" ) -- Function to handle button events local function handleButtonEvent( event ) if event.phase == "ended" and eggplant.alpha ~= 0 then eggplant.alpha = 0 physics.removeBody(eggplant, "dynamic", physicsData:get("eggplant")) end if ( "ended" == event.phase ) then print( "Button was pressed and released" ) end end local removeeggplant = widget.newButton( { width = 80, height = 40, defaultFile = "images/level.png", overFile = "images/level.png", label = "", onEvent = handleButtonEvent } ) -- Center the button removeeggplant.x = 40 removeeggplant.y = 20 -- Change the button's label text removeeggplant:setLabel( "Remove" ) sceneGroup:insert(removeeggplant) -------------------------Add eggplant button local widget = require( "widget" ) -- Function to handle button events local function handleButtonEvent( event ) if event.phase == "ended" and eggplant.alpha ~= 1 then eggplant.alpha = 1 physics.addBody(eggplant, "dynamic", physicsData:get("eggplant")) end if ( "ended" == event.phase ) then print( "Button was pressed and released" ) end end local addeggplant = widget.newButton( { width = 80, height = 40, defaultFile = "images/level.png", overFile = "images/level.png", label = "", onEvent = handleButtonEvent } ) -- Center the button addeggplant.x = 150 addeggplant.y = 20 -- Change the button's label text addeggplant:setLabel( "Add" ) sceneGroup:insert(addeggplant)