Cryptanalysis using heuristics has been found to be significant in the context of attacks of block ciphers. In the literature, lot of studies can be found in this regard. However, all those works made cryptanalysis either by using classical heuristic search algorithms or by using a slightly modified/ improved version of those algorithms. In this paper, cryptanalysis is further extended over prominent and significant block ciphers such as Direct Encryption Standard (DES) and Simplified DES (S-DES) using recently developed heuristic search algorithms such as Bees Algorithm (BA), Bacterial Foraging Optimization (BFO) algorithm and Cuckoo search (CS) algorithms. The study mainly focuses on the strength of the heuristic attacks over such block ciphers.