Need help with script

How would I get this bird to stay inside this bathroom with out bumping into wall constantly?

local Fly = script.Parent

while true do
	Fly.BodyVelocity.velocity = Vector3.new(math.random(-100,100)*0.5,math.random(-100,100)*0.1,math.random(-100,100)*0.5)
	wait(math.random(10,25)*0.1)
end

Heres a picture of the bathroom: