Hi . surely they have gotten inside, these beings always look for dark and warm places, and the boiler is a good place, what I recommend is to buy a matacucaracha syringe, which is for those little cucades German, or household flames, which are not big sewer, these little ones reproduce to the beast, if you can open it and put a few points of the syringe inside, or close to the hole where you see it come out, for every 2 you see there are 100, and the black granites you see are eggs , do not throw the coffee maker what you should do is fight them, but soon you will have it in the whole kitchen, with a syringe applying in cupboards and corners every 30 cm the changes.