diff --git a/bin/aggregate_logs.R b/bin/aggregate_logs.R
index 4de5e04..ce3c96e 100755
--- a/bin/aggregate_logs.R
+++ b/bin/aggregate_logs.R
@@ -15,9 +15,19 @@ suppressPackageStartupMessages(library(parallel))
 
 # Function to read and aggregate filter_blat logs
 aggregate_filter_blat_logs <- function(log_files, num_cores) {
+
+  expected_steps_keywords <- c("initial", "e-value", "max hits")
+
   # Read all logs into a list of data.tables in parallel and remove "Elapsed time (s)" column
   log_list <- mclapply(log_files, function(log_file) {
     log.dt <- fread(log_file, sep = "\t", header = TRUE)
+
+    missing_steps <- expected_steps_keywords[!sapply(expected_steps_keywords, function(p) any(str_detect(log.dt$Step, fixed(p))))]
+
+    if (length(missing_steps) > 0) {
+      stop(paste("Log file", log_file, "is missing required Step(s): ", paste(missing_steps, collapse = ", ")))
+    }
+
     elapsed_time_col <- "Elapsed time (s)"
     if (elapsed_time_col %in% colnames(log.dt)) {
       log.dt[, (elapsed_time_col) := NULL]  # Remove time column
@@ -50,9 +60,26 @@ aggregate_filter_blat_logs <- function(log_files, num_cores) {
 
 # Function to read and aggregate identify_hybrids logs
 aggregate_identify_hybrids_logs <- function(log_files, num_cores) {
+
+  expected_types <- c(
+    "initial_read_count",
+    "strong_contiguous_match_to_a_single_gene",
+    "excessive_overlap_in_query_mappings",
+    "excessive_gap_between_query_mappings",
+    "excessive_overlap_in_subject_mappings",
+    "remaining_read_count"
+  )
+
   # Read all logs into a list of data.tables in parallel
   log_list <- mclapply(log_files, function(log_file) {
     log.dt <- fread(log_file, sep = "\t", header = TRUE)
+
+    # Check all expected types are present
+    missing_types <- setdiff(expected_types, log.dt$type)
+    if (length(missing_types) > 0) {
+      stop(paste("Log file", log_file, "is missing expected types: ", paste(missing_types, collapse = ", ")))
+    }
+
     return(log.dt)
   }, mc.cores = num_cores)
 
@@ -61,6 +88,7 @@ aggregate_identify_hybrids_logs <- function(log_files, num_cores) {
     stop("The list of logs is empty.")
   }
 
+
   # If only one log file, return it directly
   if (length(log_list) == 1) {
     aggregated.dt <- log_list[[1]]
diff --git a/bin/identify_hybrids.R b/bin/identify_hybrids.R
index dae1b46..2b434d1 100755
--- a/bin/identify_hybrids.R
+++ b/bin/identify_hybrids.R
@@ -90,10 +90,24 @@ option_list <- list(make_option(c("-b", "--blast8"), action = "store", type = "c
 opt_parser = OptionParser(option_list = option_list)
 opt <- parse_args(opt_parser)
 
+# Prepare data for logging
+discarded_reasons <- c(
+    "strong_contiguous_match_to_a_single_gene",
+    "excessive_overlap_in_query_mappings",
+    "excessive_gap_between_query_mappings",
+    "excessive_overlap_in_subject_mappings"
+)
+
 if(is.na(readLines(opt$blast8)[1])) {
 
+    message("Empty blast8 input — writing empty output and default log.")
     fwrite(data.table(), file = opt$output, sep = "\t", col.names = TRUE) # Accounts for empty filtered blast file
-    fwrite(data.table(), file = opt$log, sep = "\t", col.names = FALSE)
+
+    log.dt <- data.table(
+      type = c("initial_read_count", discarded_reasons, "remaining_read_count"),
+      count = c(0L, rep(0L, length(discarded_reasons)), 0L)
+    )
+    fwrite(log.dt, file = opt$log, sep = "\t")
 
 } else {
 
@@ -108,7 +122,7 @@ if(is.na(readLines(opt$blast8)[1])) {
     hybrids.list <- parLapply(cl = cl, blast.list, function(x) get_valid_hybrids(blast.query.dt = x))
     stopCluster(cl)
 
-    # get_valid_hybrids returns a data.table if valid, or a character string with a discard reason if not.
+    # get_valid_hybrids returns a data.table if valid, or a character string with a discard reason if not
     discarded_bools <- sapply(hybrids.list, is.character)
 
     # message(sum(S4Vectors::elementNROWS(hybrids.list) == 0), " out of ", length(hybrids.list), " reads did not have hybrids")
@@ -126,31 +140,24 @@ if(is.na(readLines(opt$blast8)[1])) {
     fwrite(valid.hybrids.dt, file = opt$output, sep = "\t", col.names = TRUE)
 
     # Prepare data for logging
-    discarded_reasons <- c(
-        "strong_contiguous_match_to_a_single_gene",
-        "excessive_overlap_in_query_mappings",
-        "excessive_gap_between_query_mappings",
-        "excessive_overlap_in_subject_mappings"
-    )
     discarded_reads.list <- hybrids.list[discarded_bools]
 
     if (length(unlist(discarded_reads.list)) > 0) {
-        discarded_reads_log.dt <- as.data.table(table(unlist(discarded_reads.list)))
+        message("Logging discard reasons...")
+        discarded_vector <- factor(unlist(discarded_reads.list), levels = discarded_reasons) # force factor with full levels
+        discarded_reads_log.dt <- as.data.table(table(discarded_vector)) # table() will include the unused levels with count = 0
         setnames(discarded_reads_log.dt, c("type", "count"))
     } else {
+        message("No reads were discarded.")
         discarded_reads_log.dt <- data.table(type = discarded_reasons, count = rep(0L, length(discarded_reasons)))
     }
 
-    print(head(discarded_reads_log.dt))
-
     log.dt <- rbind(
         data.table(type = "initial_read_count", count = length(blast.list)),
         discarded_reads_log.dt,
         data.table(type = "remaining_read_count", count = length(hybrids.list[!discarded_bools]))
     )
 
-    print(head(log.dt))
-
     fwrite(log.dt, file = opt$log, sep = "\t")
 
 }
\ No newline at end of file