local bird_Damage_Radius = 1; -- the distance from the center of a bird that you can get hurt
local bird_Damage_Dealt = 1; -- how much damage the bird does PER FRAME to a player it's near
 
-- function called when a player is found in the birds sphere
function birdDamagePlayer(bird, player)
        -- deal (bird_Damage_Dealt) to the player, by the bird.
       
        --     TakeDamage( amountOfDamage, whatHurtThem, whatWeaponHurtThem )
        player:TakeDamage( bird_Damage_Dealt, bird, nil );  -- adding nil as the third parameter MAY be wrong
                                                                                                                -- but birds dont have weapons
end
 
function checkBirds()
        local allBirds = ents.FindByClass("npc_seagull"); -- get all the npc_birds in the map
       
        for count,bird in pairs(allBirds) do
                       
                -- get all the entities near the bird
                local entsInBirdSphere =    ents.FindInSphere(bird:GetPos(), -- the sphere center is on the bird
                                                                                                                  bird_Damage_Radius); -- the radius
                       
                for count2, entity in pairs(entsInBirdSphere) do
                        if(entity.IsPlayer()) then
                                birdDamagePlayer( bird, entity ); -- pass it on to our damage function
                        end
                end
               
        end
       
        local allBirds = ents.FindByClass("npc_crow"); -- get all the npc_birds in the map
       
        for count,bird in pairs(allBirds) do
                       
                -- get all the entities near the bird
                local entsInBirdSphere =    ents.FindInSphere(bird:GetPos(), -- the sphere center is on the bird
                                                                                                                  bird_Damage_Radius); -- the radius
                       
                for count2, entity in pairs(entsInBirdSphere) do
                        if(entity.IsPlayer()) then
                                birdDamagePlayer( bird, entity ); -- pass it on to our damage function
                        end
                end
               
        end
end
 
hook.Add("Think", "Bird Damage Checker", checkBirds); -- make the gamemode use checkBirds every frame