Researchers developed a complementary transposon tool kit for *Drosophila melanogaster* using the P-element and piggyBac transposons. The goal was to achieve complete gene knockout collections, which is a key next step in fly genetics. The P-element, a major tool in *D. melanogaster* genetics, has a non-random insertion pattern, and generating 150,000 insertions is estimated to achieve 87% saturation of the ~13,500-gene complement. The study improved both the P-element and piggyBac transposon to enhance gene tagging and disruption efficiency. Over 29,000 piggyBac and XP insertions were generated, resulting in 53% gene saturation and a more diverse set of phenotypically strong insertional alleles. PiggyBac showed distinct global and local gene-tagging behavior compared to P elements. PiggyBac excisions from the germline are precise, and it lacks the P-element bias for insertion in 5' regulatory sequences. The study incorporated three technological improvements: using an additional mobile genetic element (piggyBac), constructing vectors with splice-trap and transcriptional silencing elements, and using the female germline to alter the gene tagging spectrum. The piggyBac transposon was more efficient than P elements in generating recessive lethal mutations, with higher frequencies (17% for XP and 22% for piggyBac) compared to previous P-element screens (10–15%). Molecular and genetic analysis suggested that this was not due to multiple insertions but rather the transposon's insertion pattern or its ability to locally perturb gene function. The study compared the local and global insertion patterns of piggyBac and XP, finding that piggyBac inserted more frequently in coding exons and after the transcriptional start site. The piggyBac and XP insertions were mapped to 5,849 genes (DGC r1.0), showing a higher frequency of insertions after the transcriptional start site compared to XP and EP elements. The study found that piggyBac was more efficient in gene tagging, yielding a high rate of new hits even after 17,000 insertions. The combined piggyBac and XP collection tagged ~53% of DGC genes, suggesting that piggyBac could achieve 87% gene saturation with fewer insertions than P elements. The piggyBac transposon was found to be an efficient and practical gene tagging system in *D. melanogaster*, on par with the P element. These reagents and the associated transposon tool kit will complement existing *D. melanogaster* gene knockout resources. The study also demonstrated the utility of these tools in biological analysis of gene function in pharmaceutically relevant disease pathwaysResearchers developed a complementary transposon tool kit for *Drosophila melanogaster* using the P-element and piggyBac transposons. The goal was to achieve complete gene knockout collections, which is a key next step in fly genetics. The P-element, a major tool in *D. melanogaster* genetics, has a non-random insertion pattern, and generating 150,000 insertions is estimated to achieve 87% saturation of the ~13,500-gene complement. The study improved both the P-element and piggyBac transposon to enhance gene tagging and disruption efficiency. Over 29,000 piggyBac and XP insertions were generated, resulting in 53% gene saturation and a more diverse set of phenotypically strong insertional alleles. PiggyBac showed distinct global and local gene-tagging behavior compared to P elements. PiggyBac excisions from the germline are precise, and it lacks the P-element bias for insertion in 5' regulatory sequences. The study incorporated three technological improvements: using an additional mobile genetic element (piggyBac), constructing vectors with splice-trap and transcriptional silencing elements, and using the female germline to alter the gene tagging spectrum. The piggyBac transposon was more efficient than P elements in generating recessive lethal mutations, with higher frequencies (17% for XP and 22% for piggyBac) compared to previous P-element screens (10–15%). Molecular and genetic analysis suggested that this was not due to multiple insertions but rather the transposon's insertion pattern or its ability to locally perturb gene function. The study compared the local and global insertion patterns of piggyBac and XP, finding that piggyBac inserted more frequently in coding exons and after the transcriptional start site. The piggyBac and XP insertions were mapped to 5,849 genes (DGC r1.0), showing a higher frequency of insertions after the transcriptional start site compared to XP and EP elements. The study found that piggyBac was more efficient in gene tagging, yielding a high rate of new hits even after 17,000 insertions. The combined piggyBac and XP collection tagged ~53% of DGC genes, suggesting that piggyBac could achieve 87% gene saturation with fewer insertions than P elements. The piggyBac transposon was found to be an efficient and practical gene tagging system in *D. melanogaster*, on par with the P element. These reagents and the associated transposon tool kit will complement existing *D. melanogaster* gene knockout resources. The study also demonstrated the utility of these tools in biological analysis of gene function in pharmaceutically relevant disease pathways