Noticed a small crack between the concrete steps and the base of the house on the back patio steps leading out the house. Saw bees flying in and out so I have been spraying them and killing them off. Been spraying with Spectricide yellow jacket/ carpenter bees killer and it kills on contact. By now I have killed at least 60 bees but they still keep coming. How do I solve this problem. If i try to seal this up will any remaining bees now make other holes to escape. I will eventually need to seal but when should I try that?? Looking for suggestions. Wait till winter?? Thanks.