I have had some very unwelcome visitors lately. They are big black bugs with six legs, two spikes at the rear end and two long antennae on the head. They don't quite look like any cockroach I have seen before. Body length: 2.5 cm without rear spikes and antennae.
What are they? And how do I get rid of them? I found them inside my house although I had sprayed Mortein (outside variant) on door and sliding door thresholds.
Insect, 2.5cm long.jpg